Lists and Storage:
Listography allows you to make color-coded and topically arranged lists that are public or private as you choose. Great for to-do lists, lists of on-going projects, lists of thematically sorted links or ideas, and sharing lists with others.
Listography is not so great for unwieldy collections of links and assorted ideas. Evernote is much better for that, which allows you to quickly ‘clip’ an article, a link, or a full page and assign tags to help you find what you’re looking for later. I use a combination of Listography and Evernote to keep my immediate to-do items organized, store wish lists, and share lists of links with others (Listography) and quickly (and privately) store lots of articles, pictures, and links to access later (Evernote).
DropBox is what I use for sharing files that I will need to access elsewhere or collaborate with others on since managing permissions is easy and I can access my files on my own laptop as well as on-line from anywhere else (on one phone, too, if one has that capability). I use OpenDrive for music links.
Research and Learning:
WorldCat.org, “the World’s largest library catalog”. You can type in keywords, such as author and title names, and when you find what you’re looking for (easy since WorldCat has many options to help restrict your search), it will display a list of libraries near you that have the item in their collection and links to the catalogs of these libraries so you can find out the item’s call number and where to find it.
On the more explicitly learning-centric front, Anki is an excellent digital flash card program using a spaced repetition system (meaning, you’ll see flash cards more often that you’ve marked as not knowing or not knowing as well, and you’ll see flash cards less often that you’ve marked as knowing well).
Text: Creating and sharing text.
OpenOffice is the suite of programs I use on my laptop. Google Docs is what I use on the web and to easily access my documents (and make private or share, as desired) from anywhere without having to burn them to a disc, e-mail them to myself, or use a memory stick.
SourceForge: Over 300,000 open source software projects are included here which range from celestial simulations (Stellarium)to FTP Clients (FileZilla). Narrow down your results to find exactly the type of software you’re looking for.