bpkg is a utility that tries to simplify the process of trying out new programs from source. For most packages, this can be as simple as "bpkg <url or tarball>". bpkg will download, extract, configure, compile, install, generate a package in your system's native format, and finally integrate that package into your system's packaging system so that you can remove it cleanly. It has auto-detection for Arch Linux, Slackware, Red Hat, Gentoo, and SuSE (though not all packaging back-ends are complete). bpkg is not intended as a replacement for normal packaging utilities.
OnDir automatically executes scripts in directories when you traverse them at the command line. In addition, it also executes these scripts in any intervening directories. Use it if you are sick of typing 'umask 022' when editing your Web pages in ~/public_html, or want to add a directory to your PATH - but only while in certain directories.