Zeal - Zeal is an API Documentation Browser.
LINQPad - A scratchpad for C#, F# and VB code including Linq queries.
dasht - A collection of shell scripts for searching, browsing, and managing API documentation (in the form...
Velocity - Velocity gives your Windows desktop offline access to over 150 API documentation sets provided by...
Devhelp - Devhelp is a GTK+/GNOME browser for API documentation; it works natively with gtk-doc (which is the...
DevDocs - Open source API documentation browser with instant fuzzy search, offline mode, keyboard shortcuts, and more