gFTP is a free multithreaded file transfer client for *NIX based machines running X11R6 or later. It has text and GTK+ 1.2/2.x interfaces and supports the FTP, FTPS (control connection only), HTTP, HTTPS, FSP, and SSH protocols and has FTP and HTTP proxy server support. It supports UNIX, EPLF, Novell, MacOS, VMS, MVS, and NT (DOS) style directory listings, and has a bookmarks menu that allows you to quickly connect to remote sites. The code is fully internationalized and there are currently 45 translations available.
Cfengine is a tool for setting up and maintaining BSD and System-5-like operating system optionally attached to a TCP/IP network. You can think of cfengine as a very high level language, much higher level than Perl or shell: a single statement can result in many hundreds of operations being performed on multiple hosts. Cfengine is good at performing a lot of common system administration tasks, and allows you to build on its strengths with your own scripts.
Gri is an extensible plotting program designed for scientists. It can draw x-y plots, contour plots, and image plots, and has rudimentary programming capabilities. Output is PostScript. Gri is not mouse driven, nor GUI-based; it is a language. Users regard it as an analogue to the LaTeX document formatting language: users gain considerable power, at the price of a moderate learning curve.
Hoard is a scalable memory allocator (malloc replacement) for multithreaded applications. Hoard can dramatically improve your application's performance on multicore machines. No changes to your source are necessary; just link it in. Hoard scales linearly up to at least 64 processors. Supported platforms include Linux, Solaris, Mac OS X, and Windows.