Oblivion Mod Manager
This is a utility for managing plugins, and also for packing them for distribution. It can just be used as an enhanced version of the data files selector on the oblivion launcher, with sorting and load-order reordering capabilities, but there are a lot more features which can only be used when mods are packed as .omod files. You can easily clean all files belonging to the mod out of your data folder, view the readme without unpacking the mod, e-mail the mod author, visit their website or view detailed information about the file. The main advantage though is that an omod can contain a script which can tell obmm which other mods a mod depends on, which mods it conflicts with, the order in which the esps must load, automatically register new bsa files, make ini or xml tweaks, etc. My aim was to make it nearly impossible to install the mod incorrectly.