Recently a bunch of technologies have been released and/or updated and I would like to mention a few of them briefly.
First and foremost, Silverlight 2 Beta 1 has finally been released and you may download it immediately. There is also an accompanying SDK. You can find a nice development tutorial series on Scott Guthrie's blog. If you are already familiar with WPF, you can just skim this entire series in less than 5 minutes. Given that this technology isn't the same as the full WPF and given that it's designed for the web, there will obviously be differences. It's important to remember that Silverlight 2 isn't simply WPF for the web. I would call WPF 3.5's XBAP support for IE/Firefox "WPF for the web". No, this is possibly the biggest web technology improvement since the release of Firefox 1.0, which in turn was the biggest technology release since the printing press. Alight, alight... since .NET 1.1. It's support for the dynamic language runtime is going to completely revolutionize our web development.
When reading through Scott's tutorial series (serious, at least skim it), it's interesting to note that Silverlight 2 allows cross-domain communication. It does this by reusing the Flash communication policy files. This is really awesome as it means that you can start accessing resources that Flash has been using for a while. Being able to dynamically access resources from different domains is critical to the success of web architecture in the future.
Speaking of cross-domain communication, John Resig and I received a very depressing e-mail the other day telling us horrible news: cross-domain communication will probably be removed from Firefox 3 before it's official release. Apparently a bunch of paranoid anti-architects were complaining about the dreaded evils of being able to access resources from different domains. Um ok. Fortunately, however, Firefox 3 has a feature called postMessage that allows you to get around this. Malte Ubl has produced a library called xssinterface to demonstrate just this concept. You could, of course, get around this completely with some iframe hacks or some other scripting magic.
Speaking of web browsers, I would like to bring people's attention to a technology that I've been following for some time now: Apple WebKit. This is basically the brains inside Safari. I absolutely love the Safari web browser. It's by far and away the easiest web browser to use. It also has the same keyboard short-cuts as Firefox, which is how I'm able to use it. It's also incredibly fast, but I should mention that it uses even more memory than Firefox. My last instance passed 500MB. Given it's lack of an extension or configuration (i.e. about:config) system, it's obviously no where near the same caliber as Firefox though. It is, however, my primary web browser as has been since October '07.
The reason I mention WebKit is because as very few people know, this is an open source project and has nightly binaries released on their webkit.org web site. One of the most interesting thing about nightlies that you can actually watch the progress of development as time goes on. About every month or so I like to get the latest Firefox nightly. It's always interesting to see the major experiments that the developers try about 2 months after a major release of Firefox. There's always some really awesome "teaser" feature in there that later grows into a fully grown technology. The same can be said for WebKit.