Leanpub Header

Skip to main content

Towards a Digital Left International Against Digital Capitalism

The Digital Left in the Age of Algorithms

Towards a Digital Left International Against Digital Capitalism

Core Ideas of the Book

Capitalism has developed its tools of domination to an unprecedented degree, above all in the digital field. How, then, can the Left resist it and open the way toward a more just, humane socialist alternative, locally and globally? This is the central question the book seeks to answer.

I. Digital Capitalism: Its Transformations and Forms of Domination

1. Digital capitalism today: The world is witnessing an unprecedented acceleration in the development of digitalization and artificial intelligence, while ownership of their core tools and resources is concentrated in the hands of a handful of monopolistic capitalist corporations backed by the major powers. The domination of digital capitalism has extended from the economy and the labor market to wars, repression, and the shaping of consciousness.

2. The digital revolution and class contradiction: The digital revolution opens unprecedented horizons for human progress, from freeing people from exhausting labor and reducing working hours, to accelerating scientific research, widening access to knowledge and education, and combating poverty and disease. Yet capital's control over its tools and fruits limits these possibilities and deepens class inequality, while capitalist monopolies and the major powers seize the largest share of the gains of technological progress.

3. The non-neutrality of artificial intelligence, platforms, and digital applications: Algorithms, artificial intelligence systems, and digital platforms are not neutral. They are developed, financed, and managed within capitalist relations of production, and their design, data, and priorities reflect the interests of those who own and control them. The fundamental question therefore remains: who owns this technology, who directs it, in whose interest does it operate, and how?

4. Shaping consciousness and voluntary digital servitude: Algorithms and artificial intelligence increasingly shape consciousness, opinions, and social behavior in line with the interests of the capitalist corporations that own the platforms and of the major powers. Forms of voluntary digital servitude are expanding, as are the risks of weakening independent human thought and of turning data and human behavior into sources of profit, surveillance, and control.

5. Repression, killing, and digital fascism: Digital surveillance and control tools and military targeting systems enable new forms of killing, destruction, repression, and restriction of freedoms. The convergence between some far-right forces and technology monopolies grants dangerous capabilities to expand surveillance, disinformation, and control over societies, heightening the risks of digital fascism.

II. The Digital Left and the Foundations of Renewal and Alternatives

6. The Digital Left: The Digital Left draws on the socialist heritage and its diverse intellectual and militant experiences, foremost among them Marxism as a living analytical method for understanding relations of production, class struggle, and mechanisms of exploitation, and it seeks to develop this heritage in light of the digital revolution. Just as Marx and Engels analyzed the capitalism of their era with the tools of their time, the Left today bears the task of applying this method to the analysis of digital capitalism and its new forms of exploitation. To confront a capitalism that constantly renews itself in every field, the Left in turn needs to renew itself, and the Digital Left is an orientation toward developing it intellectually, organizationally, and practically, one that complements its existing currents.

7. Intellectual and organizational renewal: Intellectual renewal proceeds from reality to theory and reads past and existing socialist experiences critically, within their historical context. Organizational renewal includes developing decision-making mechanisms, broadening the participation of members, strengthening the presence of women and young people in leadership, and moving toward more collective, horizontal, and flexible organizational forms.

8. Integrating digital struggle and fieldwork: Digital struggle complements fieldwork and mass organizing on the ground, opening new possibilities to strengthen it and extend its impact. The strength of the Left lies in transforming communication and solidarity across networks into tangible collective action that serves the struggles of women and men workers of hand and mind and of the broad masses.

9. Left autonomy and its five pillars: The concept of Left autonomy rests on five interconnected and complementary pillars: political, organizational, financial, media, and digital autonomy. The digital pillar requires developing the Left's independent technological and digital capacities and gradually freeing it from its dependence on major capitalist platforms and corporations.

10. Digital socialism and social justice: Technology offers new possibilities for democratic planning, the collective management of resources, and a fairer distribution of wealth and knowledge, which requires defending the rights of working women and men and reducing working hours. The path to digital socialism rests on distinguishing between the ultimate goal, socialist transformation based on social ownership of all means of production, including digital ones, and the steps possible now that bring it closer.

III. The Digital Left International: Necessity, Principles, and Goals

11. The necessity of a Digital Left International: In the face of a transnational digital capitalism, Left forces acting alone find it difficult to confront the major technology monopolies that own data, platforms, digital infrastructure, and artificial intelligence systems, and that use them to deepen exploitation and control. Hence the need to build a Digital Left International that strengthens cooperation and solidarity among Left forces and coordinates their common struggles at the global level.

12. Pluralism, autonomy, and voluntary cooperation: Building the Digital Left International rests on respect for pluralism and the autonomy of organizations, the search for common ground, and the development of participatory and flexible forms of coordination and cooperation. It is a framework for complementarity and joint action, distinct from the model of a centralized world party, whose mechanisms evolve democratically according to experience and need.

13. Internationalist solidarity and organized collective action: The Digital Left International project is based on moving solidarity among Left forces from the level of positions and statements to organized practical cooperation that supports workers', feminist, human rights, and democratic struggles, confronts wars, repression, racism, and digital fascism, and links digital work to social and grassroots struggles.

14. Knowledge and technology as a public good under democratic oversight: Decisions on the development and uses of artificial intelligence and digital technology should be freed from the monopoly of capitalist corporations and the major powers, through broader democratic participation and social oversight, guaranteed transparency and accountability, and the involvement of working women and men and of users in the decisions that affect their lives. Expanding free access to knowledge and supporting open-source software and public digital infrastructure constitute an essential step toward strengthening digital justice and digital rights.

15. The Digital Left International within the broader socialist struggle: The Digital Left International represents one of the tactics of struggle against digital capitalism and complements struggle in the political, trade union, social, and intellectual fields for socialist transformation. It has today become the most important dimension of internationalist work, now that digital space has become one of the main arenas of class struggle and of control over consciousness. Its construction can therefore serve as a starting point for renewing internationalist work in other fields.

IV. From Idea to Practice: Preconditions, Practical Proposals, and a Five-Year Horizon

16. Interconnected preconditions and local building: The Digital Left International rests on complementary material, organizational, and intellectual preconditions, where a setback in any one of them weakens the others. Developing the Left digitally in each country is one of the foundations of its construction: the International is a network that draws its strength from the strength of its nodes, and every organization that builds its capacities locally adds an active node to it.

17. Independent funding and justice in the distribution of digital wealth: Conditional funding means conditional direction. Funding for the International should therefore rely on contributions from participating organizations and on mass and cooperative funding, with transparency and democratic oversight of resources guaranteed. The struggle to impose progressive taxes on major technology corporations and to redistribute the gains of the digital revolution remains part of the general demands of digital justice.

18. Digital awareness, education, skills, and legislative struggle: Building the social and technical base of the International requires a class-conscious digital awareness that moves members and the masses from passive use of technology to understanding how it works and taking part in directing it. It also requires an independent educational system, the gathering of technical talent scattered across borders into joint working teams, and a legal and legislative struggle that protects rights in parallel with building progressive alternatives.

19. The practical beginning and a democratic network structure: The International could begin with an online general meeting, open to the widest possible participation, to agree on shared priorities and initial coordination mechanisms. It would rest on local, regional, and global networks operating through democratic and transparent mechanisms, together with a digital audit within each organization to determine its level of dependence on monopolistic platforms and to set a realistic plan for gradually breaking free of it.

20. Tools of resilience, coordination, and digital solidarity: The practical proposals include a decentralized coordination network built on open protocols; a digital solidarity protocol setting out rapid-response mechanisms against repression, blocking, and digital attacks; an independent and transparent internationalist fund; a network of technical talent that protects participants and their data; and a map of existing progressive initiatives to avoid duplicated efforts.

21. Technical and knowledge alternatives and gradual development: The proposals also include specialized technical laboratories; an open, multilingual educational platform that pays particular attention to the languages of the Global South; committees on artificial intelligence; digital cooperatives; and partnerships with free software communities. Work can begin by developing and adapting existing tools, then move gradually toward building progressive alternatives in social networking, search, and artificial intelligence, according to available capacities and under democratic management and oversight.

22. Digital rights and justice, and follow-up mechanisms: The proposals further extend to a legal and human rights network for litigation before local and international courts and for drafting model laws; the drafting of a Universal Declaration of Digital Rights and Justice; an internationalist campaign against the use of artificial intelligence in wars, killing, and repression; and a gender justice program, together with a periodic digital forum that works as a workshop, and independent monitoring and evaluation units.

23. Years one and two, building the local base and regional expansion: Local work predominates in the first year, as participating organizations begin securing their communications and data and assessing their digital dependence, while the coordination network, the fund, the talent network, and the periodic forum are launched. In the second year, the center of gravity shifts to the regional level: the educational platform and the legal network are launched, the joint laboratories develop experimental tools for secure communications, and several organizations make progress in developing their internal mechanisms.

24. Years three and four, testing solidarity and building shared alternatives: In the third year, the digital solidarity protocol may undergo practical tests in confronting repression, blocking, and digital attacks, the first digital cooperatives show tangible results, and the campaign against the military and repressive use of artificial intelligence expands. In the fourth year, a shared digital ecosystem bringing together education, search, and communication is expected to develop, initial results of the legal and legislative struggle emerge, and experimental versions of progressive social networks and search platforms are launched.

25. Year five and the horizon of transformation in mass consciousness: The fifth year may see the presentation of a draft Universal Declaration of Digital Rights and Justice, the development of progressive, cooperative, open-source artificial intelligence models under social oversight, the strengthening of women's participation in building technology, and the extension of internationalist cooperation to the fields of workers' and mass struggle, climate, and anti-war action. The deepest impact, however, is likely to lie in a transformation of mass consciousness toward understanding the class nature of technology and taking a conscious part in building its collective and democratic alternatives. This picture remains a vision open to discussion, and its realization depends on collective will and the balance of forces.

Minimum price

$1.00

$1.00

You pay

Author earns

$

Also available for 1 book credit with a Reader Membership

PDF
About

About

About the Book

Core Ideas of the Book
Capitalism has developed its tools of domination to an unprecedented degree, above all in the digital field. How, then, can the Left resist it and open the way toward a more just, humane socialist alternative, locally and globally? This is the central question the book seeks to answer.

I. Digital Capitalism: Its Transformations and Forms of Domination

1. Digital capitalism today: The world is witnessing an unprecedented acceleration in the development of digitalization and artificial intelligence, while ownership of their core tools and resources is concentrated in the hands of a handful of monopolistic capitalist corporations backed by the major powers. The domination of digital capitalism has extended from the economy and the labor market to wars, repression, and the shaping of consciousness.

2. The digital revolution and class contradiction: The digital revolution opens unprecedented horizons for human progress, from freeing people from exhausting labor and reducing working hours, to accelerating scientific research, widening access to knowledge and education, and combating poverty and disease. Yet capital's control over its tools and fruits limits these possibilities and deepens class inequality, while capitalist monopolies and the major powers seize the largest share of the gains of technological progress.

3. The non-neutrality of artificial intelligence, platforms, and digital applications: Algorithms, artificial intelligence systems, and digital platforms are not neutral. They are developed, financed, and managed within capitalist relations of production, and their design, data, and priorities reflect the interests of those who own and control them. The fundamental question therefore remains: who owns this technology, who directs it, in whose interest does it operate, and how?

4. Shaping consciousness and voluntary digital servitude: Algorithms and artificial intelligence increasingly shape consciousness, opinions, and social behavior in line with the interests of the capitalist corporations that own the platforms and of the major powers. Forms of voluntary digital servitude are expanding, as are the risks of weakening independent human thought and of turning data and human behavior into sources of profit, surveillance, and control.

5. Repression, killing, and digital fascism: Digital surveillance and control tools and military targeting systems enable new forms of killing, destruction, repression, and restriction of freedoms. The convergence between some far-right forces and technology monopolies grants dangerous capabilities to expand surveillance, disinformation, and control over societies, heightening the risks of digital fascism.

II. The Digital Left and the Foundations of Renewal and Alternatives

6. The Digital Left: The Digital Left draws on the socialist heritage and its diverse intellectual and militant experiences, foremost among them Marxism as a living analytical method for understanding relations of production, class struggle, and mechanisms of exploitation, and it seeks to develop this heritage in light of the digital revolution. Just as Marx and Engels analyzed the capitalism of their era with the tools of their time, the Left today bears the task of applying this method to the analysis of digital capitalism and its new forms of exploitation. To confront a capitalism that constantly renews itself in every field, the Left in turn needs to renew itself, and the Digital Left is an orientation toward developing it intellectually, organizationally, and practically, one that complements its existing currents.

7. Intellectual and organizational renewal: Intellectual renewal proceeds from reality to theory and reads past and existing socialist experiences critically, within their historical context. Organizational renewal includes developing decision-making mechanisms, broadening the participation of members, strengthening the presence of women and young people in leadership, and moving toward more collective, horizontal, and flexible organizational forms.

8. Integrating digital struggle and fieldwork: Digital struggle complements fieldwork and mass organizing on the ground, opening new possibilities to strengthen it and extend its impact. The strength of the Left lies in transforming communication and solidarity across networks into tangible collective action that serves the struggles of women and men workers of hand and mind and of the broad masses.

9. Left autonomy and its five pillars: The concept of Left autonomy rests on five interconnected and complementary pillars: political, organizational, financial, media, and digital autonomy. The digital pillar requires developing the Left's independent technological and digital capacities and gradually freeing it from its dependence on major capitalist platforms and corporations.

10. Digital socialism and social justice: Technology offers new possibilities for democratic planning, the collective management of resources, and a fairer distribution of wealth and knowledge, which requires defending the rights of working women and men and reducing working hours. The path to digital socialism rests on distinguishing between the ultimate goal, socialist transformation based on social ownership of all means of production, including digital ones, and the steps possible now that bring it closer.

III. The Digital Left International: Necessity, Principles, and Goals

11. The necessity of a Digital Left International: In the face of a transnational digital capitalism, Left forces acting alone find it difficult to confront the major technology monopolies that own data, platforms, digital infrastructure, and artificial intelligence systems, and that use them to deepen exploitation and control. Hence the need to build a Digital Left International that strengthens cooperation and solidarity among Left forces and coordinates their common struggles at the global level.

12. Pluralism, autonomy, and voluntary cooperation: Building the Digital Left International rests on respect for pluralism and the autonomy of organizations, the search for common ground, and the development of participatory and flexible forms of coordination and cooperation. It is a framework for complementarity and joint action, distinct from the model of a centralized world party, whose mechanisms evolve democratically according to experience and need.

13. Internationalist solidarity and organized collective action: The Digital Left International project is based on moving solidarity among Left forces from the level of positions and statements to organized practical cooperation that supports workers', feminist, human rights, and democratic struggles, confronts wars, repression, racism, and digital fascism, and links digital work to social and grassroots struggles.

14. Knowledge and technology as a public good under democratic oversight: Decisions on the development and uses of artificial intelligence and digital technology should be freed from the monopoly of capitalist corporations and the major powers, through broader democratic participation and social oversight, guaranteed transparency and accountability, and the involvement of working women and men and of users in the decisions that affect their lives. Expanding free access to knowledge and supporting open-source software and public digital infrastructure constitute an essential step toward strengthening digital justice and digital rights.

15. The Digital Left International within the broader socialist struggle: The Digital Left International represents one of the tactics of struggle against digital capitalism and complements struggle in the political, trade union, social, and intellectual fields for socialist transformation. It has today become the most important dimension of internationalist work, now that digital space has become one of the main arenas of class struggle and of control over consciousness. Its construction can therefore serve as a starting point for renewing internationalist work in other fields.

IV. From Idea to Practice: Preconditions, Practical Proposals, and a Five-Year Horizon

16. Interconnected preconditions and local building: The Digital Left International rests on complementary material, organizational, and intellectual preconditions, where a setback in any one of them weakens the others. Developing the Left digitally in each country is one of the foundations of its construction: the International is a network that draws its strength from the strength of its nodes, and every organization that builds its capacities locally adds an active node to it.

17. Independent funding and justice in the distribution of digital wealth: Conditional funding means conditional direction. Funding for the International should therefore rely on contributions from participating organizations and on mass and cooperative funding, with transparency and democratic oversight of resources guaranteed. The struggle to impose progressive taxes on major technology corporations and to redistribute the gains of the digital revolution remains part of the general demands of digital justice.

18. Digital awareness, education, skills, and legislative struggle: Building the social and technical base of the International requires a class-conscious digital awareness that moves members and the masses from passive use of technology to understanding how it works and taking part in directing it. It also requires an independent educational system, the gathering of technical talent scattered across borders into joint working teams, and a legal and legislative struggle that protects rights in parallel with building progressive alternatives.

19. The practical beginning and a democratic network structure: The International could begin with an online general meeting, open to the widest possible participation, to agree on shared priorities and initial coordination mechanisms. It would rest on local, regional, and global networks operating through democratic and transparent mechanisms, together with a digital audit within each organization to determine its level of dependence on monopolistic platforms and to set a realistic plan for gradually breaking free of it.

20. Tools of resilience, coordination, and digital solidarity: The practical proposals include a decentralized coordination network built on open protocols; a digital solidarity protocol setting out rapid-response mechanisms against repression, blocking, and digital attacks; an independent and transparent internationalist fund; a network of technical talent that protects participants and their data; and a map of existing progressive initiatives to avoid duplicated efforts.

21. Technical and knowledge alternatives and gradual development: The proposals also include specialized technical laboratories; an open, multilingual educational platform that pays particular attention to the languages of the Global South; committees on artificial intelligence; digital cooperatives; and partnerships with free software communities. Work can begin by developing and adapting existing tools, then move gradually toward building progressive alternatives in social networking, search, and artificial intelligence, according to available capacities and under democratic management and oversight.

22. Digital rights and justice, and follow-up mechanisms: The proposals further extend to a legal and human rights network for litigation before local and international courts and for drafting model laws; the drafting of a Universal Declaration of Digital Rights and Justice; an internationalist campaign against the use of artificial intelligence in wars, killing, and repression; and a gender justice program, together with a periodic digital forum that works as a workshop, and independent monitoring and evaluation units.

23. Years one and two, building the local base and regional expansion: Local work predominates in the first year, as participating organizations begin securing their communications and data and assessing their digital dependence, while the coordination network, the fund, the talent network, and the periodic forum are launched. In the second year, the center of gravity shifts to the regional level: the educational platform and the legal network are launched, the joint laboratories develop experimental tools for secure communications, and several organizations make progress in developing their internal mechanisms.

24. Years three and four, testing solidarity and building shared alternatives: In the third year, the digital solidarity protocol may undergo practical tests in confronting repression, blocking, and digital attacks, the first digital cooperatives show tangible results, and the campaign against the military and repressive use of artificial intelligence expands. In the fourth year, a shared digital ecosystem bringing together education, search, and communication is expected to develop, initial results of the legal and legislative struggle emerge, and experimental versions of progressive social networks and search platforms are launched.

25. Year five and the horizon of transformation in mass consciousness: The fifth year may see the presentation of a draft Universal Declaration of Digital Rights and Justice, the development of progressive, cooperative, open-source artificial intelligence models under social oversight, the strengthening of women's participation in building technology, and the extension of internationalist cooperation to the fields of workers' and mass struggle, climate, and anti-war action. The deepest impact, however, is likely to lie in a transformation of mass consciousness toward understanding the class nature of technology and taking a conscious part in building its collective and democratic alternatives. This picture remains a vision open to discussion, and its realization depends on collective will and the balance of forces.

Share this book

Categories

Author

About the Author

Rezgar Akrawi

 About Rezgar Akrawi

Writer and Researcher

An independent leftist and the theorist of the concept of "the Digital Left," which he has developed for more than a quarter of a century and first presented under the name "the Electronic Left," the term in common use at the time. This approach rests on a central thesis: that the digital revolution is a structural transformation in the nature of power and the mechanisms by which it is produced, and that confronting capitalism in its digital phase requires intellectual, organizational and technical renewal in the very structure of the Left, and the building of a cross-border Digital Left International.

Coordinator of the Center for Studies and Research on Marxism and the Left, and founder and general coordinator of the Modern Discussion Foundation (Al-Hiwar Al-Mutamaddin), one of the most prominent and widely read leftist and progressive platforms in the Arab world.

Born: 1966, Aqrah, Iraq.

Political Activity

Active since the 1980s in several leftist parties and organizations, from the Iraqi Communist Party to the Communist Current Organization and the Worker-communist Party of Iraq, until 2000, he contributed to shaping visions for developing leftist work and strengthening coordination among its forces. He also worked within the ranks of the Danish Red-Green Alliance (Enhedslisten) between 2006 and 2010.

He believes that moving beyond traditional disagreements and focusing on common ground is a condition for any leftist revival, and calls for the founding of a unified, democratic, multi-platform leftist framework, with organizational mechanisms based on collective leadership and management and horizontal structure, and grounded in modern scientific and technological foundations and in the development of knowledge and rights.

Human Rights

A human rights activist, he was among the first contributors to the founding of the "Union of the Unemployed" in Iraq in 1992, and a member of the Iraqi Human Rights Association in Denmark between 1998 and 2000.

An advocate of the abolition of the death penalty, he is one of the founders of the "Right to Life" center, which campaigns against it in the Arab world. He has also worked on issues of gender equality and women's rights, and has taken part in numerous international conferences and meetings in these fields.

Books and Writings

Author of the book "The Most Prominent Intellectual and Organizational Foundations of the Electronic Left," in which he set out the beginnings of the intellectual and organizational framework of this current, from defining the place of digital space in the class struggle to the forms of organization and work it proposes to the forces of the Left.

In March 2025 he published the book "Capitalist Artificial Intelligence: Challenges for the Left and Possible Alternatives: Technology in the Service of Capital or a Tool for Liberation?", made freely available without copyright restrictions, and it has been translated into thirty-two other languages.

The book sparked a wide debate that extended to dozens of countries, and researchers and academics from the Arab world, Kurdistan, Italy, Greece, Turkey, Canada, the United States and elsewhere wrote about it, while its ideas were taken up in works published in other languages. This new book brings together his latest texts alongside that debate, with all the support and criticism it contained.

Publishing and Media

He has published dozens of intellectual and political articles and studies in leftist and progressive newspapers, magazines and websites.

His books and articles have been translated and published in dozens of languages, including Spanish, Portuguese, French, German, Italian, Greek, Turkish, Danish, Russian, Chinese, Hindi, Norwegian, Persian and others, and have appeared in leftist and progressive outlets in dozens of countries, from India and Brazil to Malaysia, Chile, Sri Lanka and South Africa. He has also contributed to translation and editing, and has written studies in his fields of specialization.

Technology and Digital Transformation

A specialist in information technology, he has contributed over more than a quarter of a century to building and supporting dozens of websites, platforms and digital applications for leftist and progressive organizations, human rights organizations and feminist organizations, with the aim of putting digital tools at the service of leftist and progressive thought.

Education and Academic Specialization

Bachelor's degree in Industrial Management from the University of Mosul (1989), and a Higher Diploma in Computer Science from Copenhagen International College (2000), in addition to numerous specialized courses in the internet, programming and information technology.

He works as an expert in developing e-government systems, and has long experience in implementing digital transformation projects in Denmark.

Get the free Community Edition

You can get the free Community Edition in PDF or EPUB just by sharing your name and email address with the author.

 

The Leanpub 60 Day 100% Happiness Guarantee

Within 60 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.

See full terms...

Earn $8 on a $10 Purchase, and $16 on a $20 Purchase

We pay 80% royalties on purchases of $7.99 or more, and 80% royalties minus a 50 cent flat fee on purchases between $0.99 and $7.98. You earn $8 on a $10 sale, and $16 on a $20 sale. So, if we sell 5000 non-refunded copies of your book for $20, you'll earn $80,000.

(Yes, some authors have already earned much more than that on Leanpub.)

Learn more about writing on Leanpub

Free Updates. DRM Free.

If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).

Most Leanpub books are available in PDF (for computers) and EPUB (for phones, tablets and Kindle). The formats that a book includes are shown at the top right corner of this page.

Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.

Learn more about Leanpub's ebook formats and where to read them

Write and Publish on Leanpub

You can use Leanpub to easily write, publish and sell in-progress and completed ebooks and online courses!

Leanpub is a powerful platform for serious authors, combining a simple, elegant writing and publishing workflow with a store focused on selling in-progress ebooks.

Leanpub is a magical typewriter for authors: just write in plain text, and to publish your ebook, just click a button. (Or, if you are producing your ebook your own way, you can even upload your own PDF and/or EPUB files and then publish with one click!) It really is that easy.

Learn more about writing on Leanpub