Equity in startups: Cap tables for Google, Apple, Genentech, Netscape, etc

This is a great example of the rule that "there are no rules". Here is the ordered list of Post-IPO ownership for "Officers &#38; Executives", a category which includes founders as well as execs brought on between founding and IPO.<p><pre><code> Microsoft 71.2 Ebay 60.9 Oracle 47.9 Netscape 45.4 Apple 43.4 Google 32.0 Numerical 26.9 Genentech 25.6 Yahoo 24.4 Logitech 23.1 Sun 21.2 Rambus 20.7 Riverbed 17.9 Atheros 15.7 Actelion 12.0 MIPS 10.9 Cypress 7.7 Vertex 6.1 Virata 4.1 Arm 3.7 </code></pre> So we founders, <i>IF</i> our company survives, and <i>IF</i> we remain with the company, and <i>IF</i> the company IPOs, are going to keep between 3% and 71% ownership.

Bill Gates (44.2%) , Pierre Omidyar (32.5%), and Larry Ellison (30.6%) are the top three in terms of Pre-IPO ownership. I wonder how they managed that.<p>Also, Microsoft only had 5.4% VC ownership pre-IPO.

What is the story behind the 90/10 split between Clark and Andreesen at Netscape?

As a point of curiosity, what's the usual rate of stock vesting for early employees at most small tech startups?