Clients
General Info
So which Client do you prefer? That's the BTHQ poll question right now - so go vote! I'm looking for other clients not listed and user comments about the different clients as well. To have yours listed either leave a comment after you vote or send me an email about your favorite (or lease favorite) clients.
The popularity ratings are adjusted results from a poll ran around August 2004 with a max score of 100. They will be replaced in a couple weeks with the results from the current poll. Guess its about time I run another poll on the issue.
Official Client
Popularity Rating: 36
This is the original client, the one that started it all. Its written by 
Bram Cohen, and he still releases updates from time to time. In fact, version 4 was just released in March, so if you haven't used this one in a while you might want to check it out again.
Version 4 adds some much needed features to the official client. It now has a multi-download GUI. Also, it has a sliding bar for the max upload speed, ranging from 4 KB/s (dialup) to 7.8 MB/s (OC3). Both these features have been in most other clients for some time. The max upload thing can be very important, most cable/dsl users find if this is not capped around 85-90% of your max upload speed, even tasks like web browsing can become very slow while downloading.
You can also get some more info on the torrents easily, like the tracker being used and the file list if it is a multi-file torrent. A play/pause function, viewing the peer list, easy port changing, automatic seeding guidelines, and a default download folder are also available. It also allows you to change what IP is reported to the tracker. I believe this version can download all files via a single port, like several other clients have done for a while.
While this client has some much needed additions, it still lacks the amount of the features many others now have. Things like downloading single files from a multi-file torrent can be done in Azureus or BitTornado, but not the official client. It should work great for general use or if there are compatibility issues, but power users will likely still use another client.
For more info on the new version check out the official site.
Experimental Client
Popularity Rating: 13
AKA Eike Frost's Experimental Client. In the beginning some cable users (and others too) had issues with BitTorrent hogging all their upload speed and thus made stuff like simple web browsing much slower. Since its open source, some people started messing with it. This client introduced the idea of being able to limit the speeds of your uploading to help BitTorrent from taking over your connection. However, I should remind everyone again - your download rate is proportional to your upload rate. Assuming you are not sending files to people in other programs set your upload speed to about 80% of your max upstream speed for best results.
The other thing this client added first was it minimized to the system tray in windows. This helped people downloading many files, large files, etc. keep their taskbar clear. However, it appears this program is no longer being updated.
Bit Tornado
Popularity Rating: 81
This one was formerly referred to as Shad0w's experimental client to differentiate it Eike Frost's client, and it kind of picked up where the other experimental one left off. It has the upload speed adjustment and minimize to tray options, but also several other new features.
More information on the status of the file(s): how many seeders and downloaders you are connected to, share ratings, colored indicator lights in the corner to tell you the status of the file, etc. A details link that tells you the tracker, files in the torrent, their sizes, etc. An advanced link to let you see the status of people you are connected to. A preferences link with many more options, such as an auto-resume option so you don't always have to wait for it to be checked when resuming, the ability to easily adjust the ports it uses, etc. A newer option is that it can remember what it downloaded before and do a quick resume instead of scanning forever.
This client also introduced a "super-seed" mode. Do NOT use this mode by default - it is designed for those with a complete file on a new or poorly seeded torrent to send out the parts that appear the least. "When lots of people on a torrent use super-seed,
it greatly reduces the torrent's efficiency."
eXeem
Popularity Rating: N/A
Ever wish you could combine the speeds and new file availability of BT with the easy searching and GUI of programs like Kazaa or Napster? The people who brought you suprnova.org bring you this program that tries to do just that. I have a full page of my eXeem thoughts, but I also need to warn you if you don't feel like reading that page. eXeem does contain adware (cydoor), while virtually all other BT clients are adware/spyware free. (Version 0.21 is testing a different ad system, and does not contain cydoor). It is also still in the beta stage, so it is more likely to have bugs and change drastically before 1.0 is released.
Burst!
Popularity Rating: 12
New version out now - I'll update this after I play with it a bit. This client allows you to manage multiple torrents in one place, and has a torrent spy and make torrent features integrated with it. Upload limiting settings. Now also has multi-core support and a profile system. Written by kRYPT.
PTC
Popularity Rating: 5
As with most of these in this section, it can manage all your downloads in a single window, minimize to the tray, etc. One unique feature (I believe) is a mini-bar that can let you easily keep track of your downloads, similar to compact views with some winamp skins. Upload limiting settings. If you want to be a real power user it also has a telnet interface. Development discontinued a while back.
Shareaza
Popularity Rating: 23
You may recognize this name as a traditional file sharing program capable of connecting to networks such as Gnutella2, Gnutella, and eDonkey networks. Now it works with BitTorrent too, and I believe its the only one that does this. Since this is a regular P2P file sharing program I think I should mention that you can not simply type in the latest files on BT in the search box and download like that. You still have to find the .torrent files on websites just like any other client.
Shareaza just joined the open source community with version 2. Maybe we'll start seeing spinoff programs or alternate builds before too long.
Azureus
Popularity Rating: 100
Here's the java client. Looks like one of the favorite clients right now. Again, this one allows for multiple downloads in one window, along with a queuing system. Also has a make a torrent option, as well as the health indicator lights similar to Bit Tornado's lights. It also has an embedded tracker system, which allows users to share torrents directly rather than through the external tracker. See their FAQ section for details. Upload limiting settings. Another feature this for people experiencing frequent disconnection issues is an add connections slowly option.
ABC (Yet Another Bittorrent Client)
Popularity Rating: 33
This one is heavily based on Bit Tornado. They just recently updated to version 3.0, based on Bit Tornado 0.3.10 after having a long gap between releases. So if you formerly used this but switched because of the lack of updates give it a try again. The strengths of this one are that it puts everything in a single window and adds some "global" options for upload speeds and such. It also has a queuing system with priorities you can set. Supports super-seeding, and has a create torrent feature. Text colors are the same as the health indicator lights on Bit Tornado.
Bit Spirit
Popularity Rating: 6
Looks like this site has bandwidth issues near the end of the month from time to time... Anyway - looks like this one is similar to some of these others with the listed features - single interface for multiple downloads, speed controls, etc. Also supposedly helps you organize files by categories and schedule downloads. Website may be down from time to time.
Turbo BT
Popularity Rating: 1
Starting to sound like a broken record, but its got many of the same things as all the rest in this section. Single window interface, upload limiting settings, queue support. Also has an auto shutdown computer when complete option.
Torrent Storm
Popularity Rating: 15
Again, many of the same fearures based on Shad0w's Bit Tornado. Single window interface, upload limiting settings. Also remembers torrent files and has a quick resume feature. Color indicator lights similar to those in Bit Tornado again.
Bit Comet
Popularity Rating: 7
This is a C++ based client, and is not open source. "Seriously speaking, BitComet is totally an independent work, no relation with other bittorrent clinet except the protocal" according to their FAQ. Has a quick resume option, speed limits, only uses one port for all downloads, and some other things. Check the website for more info.
BT ++
Popularity Rating: 11
Client not recommended - it is not being updated any longer and is based on a obsolete core. This one was pretty much DOA. It was one of the first to mess with the idea of multiple downloads in one window, but it never really got past being buggy.
