VeryCD - (Open Source)
First steps in the peer-to-peer field should be done with easyMule, a great software for sharing files which also allows to watch videos while downloading.
easyMule is a P2P open source software based on eMule, enabling the sharing of resources. Users can search on a dedicated engine to download files. The application speeds up the transfers, allows playback while downloading, sets buffer to protect the hard disk and more.
The interface is simple and intuitive offering the possibility to upload and share data with LowID.
The configuration of this software is easy and installation takes a few minutes.
Added: Links helper app enhanced.