Zero Install is a decentralized cross-distribution software installation system. It allows software developers to publish programs directly from their own Web sites, while supporting features familiar from centralized distribution repositories such as shared libraries, automatic updates, and digital signatures. It is intended to complement, rather than replace, the operating system's package management. 0install packages never interfere with those provided by the distribution.
libguestfs is a set of tools for accessing and modifying virtual machine (VM) disk images. You can use this for viewing and editing files inside guests, scripting changes to VMs, monitoring disk used/free statistics, P2V, V2V, performing partial backups, cloning VMs, and much more. libguestfs can access nearly any type of filesystem including: all known types of Linux filesystem (ext2/3/4, XFS, btrfs, etc.), any Windows filesystem (VFAT and NTFS), any Mac OS X and BSD filesystems, LVM2 volumes, MBR and GPT disk partitions, raw disks, qcow2, CD and DVD ISO images, SD cards, and dozens more. libguestfs doesn't need root permissions.
MLdonkey is a multi-platform, multi-network peer-to-peer client. It supports several large networks such as eDonkey, Overnet, Kademlia, Bittorrent, Gnutella (Bearshare, Limewire, etc.), Gnutella2 (Shareaza), or Fasttrack (Kazaa, Imesh, Grobster). Networks can be enabled or disabled. Searches are performed in parallel on all enabled networks. For some networks, each file can be downloaded from multiple clients concurrently.
Frama-C is a suite of tools dedicated to the analysis of the source code of software written in C. Frama-C gathers several static analysis techniques in a single collaborative framework. The collaborative approach allows static analyzers to build upon the results already computed by other analyzers in the framework. It provides sophisticated tools, such as a slicer and dependency analysis.
Orpie is a fullscreen RPN calculator for the console. Its operation is similar to that of modern HP calculators, but data entry has been optimized for efficiency on a PC keyboard. Features include extensive scientific calculator functionality, units support, base conversions, command completion, configurable keybindings, and a visible interactive stack.
Planets is a fun, interactive program for many-body gravity simulations. The emphasis is on play: it's easy to add in planets, zoom in and out, change the physical constants, save and load configurations, etc. It's designed to be easy enough for a kid to enjoy, but that hardly precludes adults.
SRESI is a smart bookmark manager. It currently sports both a command-line and a PHP interface. It works with both the standard hierarchical trees and the new and fashionable tagged bookmarks. It was developed as a way to interface both representation systems. SRESI can use Del.icio.us, Mozilla, Opera, and XBEL bookmarks, and handles a few more exports besides. Directories and tags are used equivalently, and the final hierarchies are inferred from actual tag use.