Why are seemingly no IM clients compatible with each other for anything other than simple chat?

March 22, 2005 2:32 PM

Why are seemingly no IM clients compatible with each other for anything other than chat? (i.e., file transfer, image insertion, file transfer, oh, and also file transfer.) I'm not talking about Y!IM vs. AIM here -- I'm talking about the various clients that all use AOL's IM service. Even the open-source clients have this problem. Why wasn't this problem solved years ago?
posted by tweebiscuit to Computers & Internet (8 answers total)

Response by poster: Sure, there's e-mail, but transfer-over-IM is incredibly more convenient in many situations. When I'm working on a project with my web-design partner, I can't live without iChat's image insertion feature. File transfer over IM seems like it should be such an easy feature, so it surprises me that it's still so unreliable even after IM has been so ubiquitous for so long. If there were a client that were compatible with every other client, I would switch to it in a flash -- so why haven't they gotten their act together?
posted by tweebiscuit at 2:38 PM on March 22, 2005

Because they're using a "big enterprise" mentality--if you were using any third-party AIM clients more than a couple of years ago, you'll remember that for the longest time, AOL kept tweaking the back-end interface to their IM servers to continually break those clients completely. Your connectivity would stop working, and then you'd need to upgrade, over and over again.

They were trying to keep a captive AIM audience on their own app, where they could serve ads, etc. Don't forget that the proprietary client actually serves as a revenue generator for them, when they show you ads, so if you use a third-party client, they don't get to claim you as traffic on their client.

Nowadays, they've taken a step back from that, and while they'll let the third-party apps connect reliably for the sake of keeping market share, they're not doing much to help them offer all the bells and whistles like file transfer. They're still happy with a situation that _encourages_ people to switch to AIM proper.

That, and just crappy programming. AOL's never been known as a bastion of clean coding, so I wouldn't be surprised if even if they decided to throw the doors wide open, that stuff still didn't work for anyone without access to the internal code.
posted by LairBob at 3:39 PM on March 22, 2005

Response by poster: Yeah, a lot of that makes sense. Also, my assumption is that file transfer doesn't piggyback on AOL's service (like IMs themselves do), but are client-to-client, meaning that each client has to come up with its own implementation. What I can't understand is why all the independent and open-source clients -- Trillian, gaim, Adium, iChat, Jabber, and the rest -- haven't gotten together to work out a standard so that they're at least compatible between each other.
posted by tweebiscuit at 3:45 PM on March 22, 2005

Best answer: Because there are two different AIM protocols, TOC and Oscar. TOC is an open protocol and implements basic chat functionality. Oscar is a closed protocol which implements all of the functionality available in AIM. File transfer is one of the features implemented in Oscar but not in TOC.

AOL considers Oscar proprietary technology, and makes no effort to allow non-AOL clients to use it (since they want you to use their own client). When Oscar is supported in a third-party client, it is because some developers have reverse-engineered the binary Oscar protocol and implemented it themselves. Since they're on their own in figuring it out (even without AOL actively interfering), core chat/presence features get prioritized over more distant ones.

There's a good overview of the AIM protocols and history here. The GAIM developers also address their Oscar and TOC in their page on supported protocols.
posted by mendel at 4:04 PM on March 22, 2005

When Oscar is supported in a third-party client, it is because some developers have reverse-engineered the binary Oscar protocol and implemented it themselves.

Or because they have licensed it from AOL, e.g. iChat.
posted by kindall at 4:27 PM on March 22, 2005

Response by poster: So if iChat licensed file transfer from AOL, why can't I transfer files to AOLIM users? Maybe I just happen to only try to transfer to firewalled users?
posted by tweebiscuit at 5:18 PM on March 22, 2005

I use Gaim and I have been able to "send file" to AIM users and receive from about half. However, I do wish AIM's "get file" was available so I could browse and download at my convenience.
posted by foraneagle2 at 5:29 PM on March 22, 2005

For what it's worth tweebiscuit...

I transfer images to my brother and it's fine (me ichat, he AIM).

I would think, though, that there is the possiblity of your co-worker/friend not using the latest version of AIM.

Just a thought, mind you.
posted by filmgeek at 6:21 PM on March 22, 2005