As a desktop user, you might not need this a lot. Sometimes when you have a new version of a software that's really cool but a bit buggy and you keep the old ve

As a desktop user, you might not need this a lot. Sometimes when you have a new version of a software that's really cool but a bit buggy and you keep the old version to get work done. Case in point: Blender 2.4 vs. 2.5. As a programmer, I would need this all the time. Sometimes you need several versions of a certain programming library or language implementation like Python or Ruby interpreters. I also need several versions of GCC, I have one native compiler for C++0x, a cross compiler x86_64-pc-elf for my hobby operating system project and another cross for arm-eabi-none that I use to hack system-on-chips at work. I get my GCC from Git sources. Nix (http://nixos.org/ http://nixos.org/) is a package manager that allows you to install multiple versions of the same software. NixOS is a Linux distro based on that package manager. You can also use Nix in your home directory on top of another distro. Unfortunately I have not had the time to try Nix. Anyone else tried it? PS. I was visioning a "versionless package manager" that downloads sources from Git repos, builds and installs them and keeps the build files for fast updates via incremental build. I only need a name for the thing, which is better: "vpm" or "dll hell 2.0"?