HTTP is one of the most successful protocols in the world, and more and more developers are using it to do more than drive HTML UIs (calling their systems RESTful with various degrees of justification). In a new presentation, recorded at QCon San Francisco 2008, HTTPbis WG chair and Principal Technical Yahoo! Mark Nottingham gives an update on the current status of the HTTP protocol in the wild, and the ongoing work to clarify the HTTP specification.
Mark starts by emphasizing that protocols are hard, and one is doomed to repeat the mistakes of the past if one doesn't understand them. He then dives into a brief history of HTTP and it's versions, both those that are widely deployed as well as those that remained a goal that was never achieved, such as HTTP-NG. He explains why the HTTPbis effort came into existence, and describes its goals. He then describes some areas where the ambiguity or lack of detail in the current specification has led to problems in the deployed Web, and how the working group adds detail to the specification to improve this.
The many topics covered include the level of support for various HTTP methods, the (lack of) usefulness of inventing one's own methods, URI lengths, way to get around limitations in intermediaries, redirect support with POST, cookies, caching, and authentication. Mark also briefly touches upon some newer efforts, such as standardizing a PATCH verb and link headers.
Watch Mark Nottingham's full talk to find out why HTTP is still exciting.