Ok, every flame-war about Swing vs SWT and how IBM is trying to sink Sun's boat aside, SWT is a pretty interesting toolkit. It's one of only two major Java GUI APIs available today (I'm not counting AWT as "major" anymore). Also, it's really only the second cross GUI development toolkit in any language which seems to have gotten native peering right (wxWidgets being the other one). Yet, despite all this "cool ooze", SWT adoption remains fairly low.

Eclipse itself is really the biggest application to use the toolkit. However, since SWT was originally built for Eclipse, we can pretty much discount Eclipse as factoring towards our mini mental poll. So, with Eclipse out of the way, I can think of two fairly popular apps (just off the top of my head) which use SWT: Azureus and RSSOwl. One of these applications (RSSOwl) is using the RCP as the basis for its architecture, and since using the RCP entails usage of SWT, we probably should demote RSSOwl down to ¾ of a vote.

But even weighting all things equally, that's still only two applications. Now, there are more that I wasn't able to remember right off the top of my head. And of course, there are a number of commercial and internal offerings utilizing the Eclipse RCP (I should know, I just spent the last month and a half helping to judge them for the Eclipse Awards). But while these are significant applications, and the RCP (and by proxy SWT) wouldn't be where it is without them, they don't really count as "major" end-user desktop applications.

Now, looking at SWT's main competitor, Swing, we read quite a different story. A large number of desktop applications exist which use Swing as the foundation for their UI. Just to pick a few examples: LimeWire and Columba. LimeWire being of course the wildly popular music sharing application, while Columba is a slightly less well-known email client (really nice client, just doesn't seem to work right on Windows). I just picked these applications out of thin air. Since we considered Eclipse for weighting on SWT's side of things (discounted because of SWT's origins), we should probably consider the two other majors IDEs, NetBeans and IntelliJ.

We can't actually "throw away" either NetBeans or IntelliJ simply because they are IDEs. Remember, we only discounted Eclipse because it is the reason SWT exists. NetBeans - while it is a Sun product - had nothing to do with the creation of Swing. Additionally, it really had no more to do with its growth and development as an API than any other major Swing-based application. Therefore, we have to throw both NetBeans and IntelliJ into the mix of Swing applications.

In fact, if we were to tally it all up (which I won't), we would find that Swing adoption so far outstrips SWT adoption that comparing the two is almost ludicrous. SWT really has a long way to go before it's a serious threat to Swing in terms of the "first choice" GUI API on Java. I guess the main question to which I keep returning is: Will SWT ever make it?

Please don't misinterpret this post. I love SWT as a toolkit. I think its API has some quirks, and it is limiting in some ways in which it doesn't need to be, but overall I think it's pretty cool. I also really like applications that are built using SWT - on the whole. I mean, Romain Guy is fond of saying that all SWT applications have to look like Eclipse. And while this is by no means true, I can see how he arrived at that conclusion. A lot of RCP applications neglect their look and feel a little bit since "the RCP handles it all" or some such excuse. All this does is hurt the application's adoption and spreads misconceptions about SWT in general.

Perhaps this is why SWT can't seem to break into the big time: there's just too much FUD surrounding it. If your employer were considering a new application and started asking around regarding SWT vs Swing, he'd get a hundred different answers; all of them passionate and (in some cases) very inflammatory. No one seems to be able to give a straight answer regarding either SWT or a comparison between SWT and Swing. This probably scares managers off a bit. And since Swing is bundled with the JRE, people are more prone to trusting it, and so its adoption will always remain high, and SWT will always trail it in mindshare. Thoughts?