This is not so much off-line software for your computer , as more online applications, but i thought the list is really impressive, so i am sharing it here too:
http://mashable.com/2007/09/08/5000-resources-to-do-just-about-anything-online/
"Since May 2007, we’ve been bringing you resources and tools to be more productive on the web. Due to popular demand, we’ve brought all these lists together into one gigantic meta-list: 5000+ Resources to Do Just About Anything Online. "
I havent tried out all 5000+ links, only clicked on a few hundred, and can already say, not all of the links are valid anymore.
Alas, that's part of web2.0 and beta-stage label are virtually on all of these online application.
