PlentyOfFish.com - Markus Frind<p>He has help now (although I believe it is still under 100 employees), but I believe he still plays a very integral role in the day-to-day development of the site.
You'll probably find a few good ones in the old recurring income threads: <a href="https://news.ycombinator.com/item?id=7094402" rel="nofollow">https://news.ycombinator.com/item?id=7094402</a>
Do you mean "still only maintained by the one"
Or just that the originator still participates?<p>If the former, I don't really think there are any. If the latter, there are tons of examples ranging from Dropbox to Facebook. The "still only" is almost antithetical to anything beyond very small scale success.