voltage is a BitTorrent client written entirely in PHP. It uses the socket_ functions which are typically available in most PHP environments.

• Works in places where you can't install things or run binaries
• Supports low memory usage and is memory_limit aware
• Simple piece cache system
• UDP and HTTP tracker support (UDP not available in some hosting)
• Automatically resumes download
• Supports download from only an info_hash (currently only uses itorrents.org)

Download a release from Github and extract it:

wget -O voltage.tgz https://github.com/krisives/voltage/archive/master.tar.gz
tar xf voltage.tgz
mv voltage-master voltage
cd voltage

Downloading Ubuntu 15.04 via torrent:

mkdir downloads
./voltage downloads FC8A15A2FAF2734DBB1DC5F7AFDC5C9BEAEB1F59