In Computer Magazine (Dec2001), I read an article called :"Using Open Source for a Profitable Startup".

The author (David Wall) discusses how he used opensource software (Apache, Jakarta, PostreSQL,Linux...) and Java to write the software of his new company (http://www.yozons.com/)
I found another version of the article online here :
http://www.infoworld.com/articles/su/xml/01/10/15/011015suopen.xml

I came to the same conclusions as the author when thinking about about a technical infrastructure for writing an open source application for myself. The only difference is that I'd prefer php for reusing complete applications like www.postnuke.com or www.phpgroupware.org