Danish CMS vendor Sitecore released their new version 6.3 last month. For me, the immediate question always is: how much has changed? It's only a dot release, so it shouldn't be anything major, right? Well, don't let the version numbers fool you.

When I get briefed on new versions of software, vendors are often a bit apologetic when they can't point out some cool new features or interface updates. It's almost as if they're used to briefing people that don't really care all that much about the inner workings of a system. I find that somewhat amusing, since to us, the innards of any system represent a significant part of the whole.

Point in case is Sitecore's 6.3 release. The headline would read something like "adds support for cloud" -- more specifically, Microsoft Azure (with others to follow). Dig a little deeper, and you'll also come across a "more efficient" clustering of content management servers, the machines that provide the editorial interface.

In order to support that, Sitecore has had to do quite a lot of refactoring of the internal infrastructure. 6.3 introduces an "event queue." Basically, the server will signal events (e.g., saving a content item) to the database, and the database will sync this to other servers. This means 6.3 has a lot more flexible scaling options than previous versions. You could, for instance, install one server in the US, and one in Europe; editors would have a faster connection to the server closest to them.

However, when I hear that an "event queue" has been added into the mix, I shiver a bit.  I respect Sitecore's usually pretty thorough design and development, and would expect them to get this right. But there are plenty of things I could imagine to go wrong, from small hiccups to large stumbling blocks. I've seen those in plenty of systems that use similar queueing. The key thing here, therefore, is that we won't know until 6.3 is battle-proven in some large scale deployments.

So why is this a minor release, and not -- considering the architectural implications -- a major one? According to Sitecore, versioning is based on "impact on existing implementations," i.e., backwards compatibility. That's sensible; but in this case, don't let it fool you. Sitecore 6.3 adds a lot of potential; potential for flexible scaling, but also potential for choking. We'll be watching to see how it fares in real life scenarios.