Conversely by focusing on just rails, you effectively eliminate large swaths of the enterprise market. There's a huge opportunity there for someone who can integrate across platforms and technologies, particularly if you can ship a behind-the-firewall solution.

Another Skylight founder here.

Focusing on Rails lets us build a really awesome end-to-end solution that works out of the box. Building an intuitive, explorable interface means constantly considering the application's context, and I can attest to the fact that every time we do UI, nitty-gritty details about how our customers build their applications can often become the dominant consideration. When I use general-purpose solutions that are designed for "all languages and platforms", I am often very frustrated by the resulting lowest-common-denominator APIs and UIs.

We may eventually build versions of Skylight for other platforms, but if we do, we will apply the same level of care and design for other platforms as we have done for Rails. Among other things, that will mean having team members who have written large applications in those platforms, and letting those team members drive the APIs and design for those platforms.

Sounds like a promising future, and the only sane way to approach that level of integration.