I know that the original question was “Who are the top 5 OSS thought leaders”, and that’s been covered by several folks already. I’m going to ask a similar, but different question.

Who are the top 5 entities that have brought OSS into everyday (enterprise & commercial) use? This is less a list of Thought Leaders than it is a list of Action Leaders. I don’t usually read the blogs of “people” on this list, but their efforts have changed the IT marketplace. Although you could argue that a thought leader is someone who was preciously an Action Leader….anywho.

<drumRoll>In no specific order:</ drumRoll>

1. PHP guys (Rasmus Lerdorf, Zeev Suraski & Andi Gutmans): How many websites you use today are running PHP? PHP enabled a whole class of “non-techies” to become techie enough to throw up a website with dynamic content or modify existing templates and a legion of startups to get stuff done quickly and on the cheap.

2. IBM & HP: It’s unlikely that Linux would have received enterprise acceptance from CIOs without the backing of major IT vendors such as IBM & HP. The growth of Linux no longer relies on the blessing of major IT vendors, but without the early investments and advertising from IBM & HP, it’s hard to say we’d see Linux adoption where it is today. And both have continued to support OSS by their participation in OSS projects, contributing code, paying key OSS developers to work on their respective OSS projects, and driving revenue from hardware, support and services around OSS. (Note: I’d say IBM has done more around OSS than HP, but that’s because I’m more familiar with IBM’s efforts.) Oh yeah, IBM & HP benefited nicely from their backing of Linux & OSS….nothing wrong with that :-)

3. Stallman/Linus: Hard to have an OSS list of any kind, especially a list that deals with action & results, without Stallman & Linus on it.

4. Marc Fleury: Like him or not, he woke up the middleware market. While many vendors were happy to watch Linux eat into Solaris & Windows accounts (although the latter didn’t happen as much as it is believed), the thought of OSS moving up the stack was really an afterthought. Fleury helped change that view. He made it easier for other OSS vendors to get funding, and forced software vendors (middleware or otherwise) to build strategies that used OSS in order to increase customer choice.

5. Google & Yahoo: How much of Yahoo’s and Google’s infrastructure runs on OSS? We’ll never really know for sure (although many reports indicate it’s a lot), but millions of users get to benefit from their use of OSS to deliver useful tools like GMail, Search, Yahoo Finance, del.icio.us, etc.

[The Pic is from Flickr user powerbooktrance. It’s an “Action” figure & I’m looking forward to the Transformers movie. Oh happy childhood memories.]