Horacio Fernandez is the 500th hacker committing code to LibreOffice, since September 28, 2010 (source: Ohloh). The growth has been impressive: 500 developers in 660 day, or 3 hackers every 4 days (including week ends, and festivities).
The number refers to code hackers developing code – features and patches – and to people committing localizations and dictionaries, which are an integral part of LibreOffice.
I think the best answer to this question has been provided by James Duncan Davidson on January 13, 2000, with a message on the Apache Jakarta mailing list:
However, open source is chaotic. With its special magic comes a different reality. This is:
1) People work on their own time (even people paid by a company can be considered to be working on their own time in this situtation, as each company is going to have different cycles and things they want).
2) People work on what they want to. If you are working on your own time, you are going to do what you want or you do something else.
3) Some people are evolutionaries, other are revolutionaries, and some are both at different times.
4) Both approaches are important and need to be cultured.
5) You really can’t afford to alienate any part of your developer community. Innovation can come from anywhere.