BitComet is a P2P file-sharing freeware fully compatible with BitTorrent protocol, which is one of the most popular P2P protocols designed for high-speed distribution of variously sized files ranging form a few MB to several GB. BitComet is a powerful, clean, fast, and easy-to-use BitTorrent client.
The core of BitComet is completely written in C++ (STL), one of the most efficient languages. This makes it quite different from the original client (written in Python), and those written in Java or other languages. The development of BitComet began in Aug, 2003. After more than two years' hard work, the core was stable and fast with very low CPU usage. It was reported that it can even work smoothly even on AMD K6 266MHz MMX with 128M RAM.
BitComet is designed for multiple simultaneous downloads. Because of the efficiency of the core, it can run a lot of tasks simultaneously. It was reported by a site administrator that it runs well while having more than 100 simultaneous uploading tasks. Moreover, you can even select the files to download in a torrent and set download priority for them.
The function of Intelligent Disk Cache is one important reason why people choose BitComet. It is designed for fast downloaders. When the upload or download rate exceeds 500kB/s, a carefully designed disk cache mechanism in BitComet will greatly improve the hard-disk performance by decreasing the read and write frequency of your hard disk. Therefore the life time of your hard disk will be longer. Some statistics of the operation of the cache are available in the Statistics tab, e.g. HitRatio, Read/Write Request Frequency, Actual Disk Read/Write Frequency, where one can easily find out the improvements.
Another advanced function regarding disk performance is Intelligent Disk Allocating. BitComet doesn't have to make time-consuming disk allocation operations as some of others clients do. The difference is that BitComet doesn't need to allocate disk space little by little, it can allocate space by blocks in a previously reserved space. As a result, BitComet can decrease to almost zero the disk fragmentation caused by downloading.
A list of the most important features available in BitComet can be found in the BitComet Feature List topic.
The Official Site: http://www.bitcomet.com/