PHP feels like it will be around and legacy support will be needed in the future. The addition of mobile technologies and companies like phone gap mean that almost any technology will be just fine. Since most likely CAD applications won’t be too popular on phones seems like there might be more business applications for UX/UI stuff integrating back-ends with new front-ends. PHP isn’t the fastest development platform and although it seems less commercialized than Ruby I can’t decide whether to jump ship and move to the new technology with more commercial support or stick with PHP and continue learning the various open-source frameworks and CMS. At very least, the conglomerate of the experience would allow decisions made on choosing other technologies easier since they are really very similar. When project scope comes into play PHP is a solid choice while Ruby is a cost/benefit battle still(1 note on that I like the information about RoR interpreters that could soon be compilers)