For the first 11 years of my professional career I designed and built applications using HTML. When I first started out, I mostly just specified the application design, having other people much smarter and talented than me do the coding and graphic design, and I would write the HTML myself (back in the day web "programming" was done in C in the form of CGI scripts which was nothing I wanted anything to do with). With Microsoft's Active Server Pages I graduated to performing the coding, too, which was a boatload of fun.
Enter the era of the Rich Internet Application (RIA). Adobe Flex 3 was released in June, 2007 with a much improved developer feature-set and no longer carried a server licensing requirement. It was way more powerful than the state-of-the-art HTML being used then and many, many web development projects were transitioned from HTML to Flex. Flex's popularity grew for several years and inspired Microsoft's own RIA entry, Silverlight. It seemed as though the future of web applications would be written for browser plug-ins. My own career took a slightly different turn at this point, and for two or three years I worked on .NET WinForm applications but have now found myself on a Flex project for the past little while.
Recently, I've had the opportunity to return to my roots and begin working on a brand new web application. Ah yes, HTML - my old friend. I cracked my knuckles and sat down to dig into everything that was new and wonderful in the world of web development. Even though I had made it a point over the years to stay up-to-date on the terms and technologies being used and advanced in the HTML world, I had no reason to actually learn about them in any depth. So I started to bootstrap my new application, and I have been awash in the staggering number of current techniques that are employed in modern web application design. This ain't your daddy's HTML.
And it's not over yet. The server programming model that I came to know and love, ASP.NET, is completely unrecognizable these days. While the old WebForms model still exists and is still getting some love from Microsoft in the latest .NET 4.5 release, the current wonder-child is ASP.NET MVC (which stands for Model-View-Controller). Today, you would be ruthlessly ridiculed if you started a new project using WebForms. ASP.NET MVC does away with the old server control and viewstate style of development and developers now (one could say "again" since the old Active Server Pages framework had the same benefit) have complete control over the HTML output rendered by the server. And the MVC system aims to provide a better "separation of concerns" among the various classes on the server, ostensibly making automated unit-testing a much easier task. Unfortunately, all the skills I learned about handling the WebForms Page object and event model are now completely useless, and so are all the third-party server control libraries I used. But hey, I wouldn't be in this business if there wasn't something new and exciting every other week.
I'm already exhausted just writing this post, and I haven't even mentioned Entity Framework - Microsoft's latest data-access technology du jour. So if you're like me and used to be a web developer back in the glory days of the mid-2000s, then moved into other work and are now back in the HTML world, prepare yourself for a lot of re-learning. The game has certainly changed, but I don't think there's ever been a better time to be a web developer. More capabilities, more utilities, more frameworks, more power!