* multitracker support
* serves multiple torrents on a single port and a single thread
* supports http proxies and proxy authentication
* gzipped tracker-responses
* block level piece picker
* queues torrents for file check, instead of checking all of them in parallel
* uses separate threads for checking files and for main downloader
* upload and download rate limits
* piece-wise, unordered, incremental file allocation
* fast resume support
* supports files > 2 gigabytes
* supports the no_peer_id=1 extension
* support for udp-tracker protocol
* number of connections limit
* delays sending have messages
* can resume pieces downloaded in any order
* adjusts the length of the request queue depending on download rate
* supports compact=1
* selective downloading
* ip filter