Paul Allen's 2011 memoir, published by Portfolio/Penguin, is the only first-hand account of Microsoft's founding from the side of the partnership that did not write its own story. Allen covers his childhood at Lakeside School, the Traf-O-Data years, the Altair BASIC demo, and Microsoft's early growth, alongside his later life as a venture investor, sports-team owner, and philanthropist. He was diagnosed with Hodgkin's lymphoma in 1982 and left Microsoft the following year.
The Gates shelf note calls Idea Man 'the only first-hand account of the founding from the other side of the partnership' and notes that it contains 'the most contested passages about how the founding equity was divided and how the two of them argued.' Allen's version of the equity split — he claims Gates and Ballmer diluted his stake while he was being treated for cancer — differs materially from the story told in Gates's orbit.
For a founder, the book is valuable as a counter-narrative to any single-founder origin story. Allen portrays himself as the idea person and Gates as the closer — a division that looks natural in hindsight but was fraught, undocumented, and nearly broke the partnership. The lesson is not about who was right; it is that oral agreements between teenage friends become legally ambiguous under pressure, and that a co-founder who cannot work for a period (illness, family, burnout) has no contractual protection unless one was written before the need arose. Allen's later career — investing early in AOL and Ticketmaster, building the world's largest yacht, funding the Stratolaunch aircraft, creating a brain-mapping institute — is also a case study in what a Microsoft-sized fortune enables outside the company that produced it.