Fresh data on the market share of BitTorrent clients shows that uTorrent remains the client of choice for most BitTorrent users in the West. A sample of more than half a million unique peers further shows that Transmission is gaining ground, while the once so popular BitComet client slowly fades away.

With millions of people using BitTorrent every day, the protocol has been the leading P2P technology from more than half a decade.

To gain more insight into BitTorrent’s usage we’ve previously looked at the market share of various BitTorrent clients to spot emerging trends, and today we revive this initiative. To see where things stand two years after our last report, TorrentFreak asked the Tribler P2P research team at Delft University of Technology to find out which clients are being used in various popular BitTorrent swarms.

Although the new results show some interesting shifts in market shares, uTorrent remains firmly in the lead. Nearly half of the 557,536 unique peers (48%) that were spotted in the sample were using a version of uTorrent. The mainline client, also developed by BitTorrent Inc., came in at third with a market share of 13 percent.

Vuze, formerly known as Azureus, secured second place with 22 percent of the total users. This is an all-time high for the client which had just 14 percent market share in our last report. One of the factors that contributed to this rise is FrostWire’s move to become a BitTorrent-only client based on the Azureus code base. This means that a few percent of the downloaders that identify as using Azureus, are in fact FrostWire users.

Another client that gained popularity is Transmission, which doubled its market share in recent months and is now at 7 percent. A respectable figure, especially because Transmission doesn’t have a native Windows client. BitComet, on the other hand, continued its downward spiral and is now stuck at little over one percent, down from the 6 percent it enjoyed two years ago.

We have to note that the comparisons above are relative. The number of BitTorrent users has grown significantly over the past two years, so in absolute numbers Transmission’s user base may have even quadrupled, or more.

Below is the full list of all clients that have a market share over 1 percent. Some clients were not identified by libTorrent (rakshasa) and those ended up in the unknown ‘category’. As before, the research focuses on popular swarms listed on English language BitTorrent sites, which means that ‘foreign’ clients such as Xunlei are underrepresented.