netjukebox is a Web-based media jukebox for MPD, VideoLAN, and Winamp/httpQ. It features realtime MP3 streaming from different audio formats. Users can download single tracks or a whole album in one zip file. It is also possible to batch-transcode the whole music collection to another format or bitrate without touching the original files.
PerlShare is a DropBox drop-in to create your own private file sharing "cloud". It consists of two parts; a client and a server. The server part lets you configure a Linux machine to accept PerlShare clients. PerlShare behaves a lot like DropBox. On collisions, for example, it creates conflicted copies. The workhorse for synchronization is Unison, a very reliable piece of software from Pascal Bach.