Joomla and Drupal are CMSes, written in PHP. You may want to read up on Drupal having teething troubles with MySQL and the way their tables are structured, considering huge changes to the system, hitting a wall in the process. Joomla is no better. It's a great system to play around with, but it's painful to see their 'templates' looking just like each other. And none of these systems can really do a site that is based on static pages, which are a big boon on a heavy traffic website.
Expressions Engine (old pMachine www.pmachine.com) is a very well structured software, but a pain in the butt to customize to a point where cruft-free URLs work and the system is intuitive. Yes they have forums and wiki integrated into the base code, but these wiki and forums are half-baked at best. (The best forum software bar none is PunBB -- www.punbb.com -- should you ever need one, not even SMF comes close). Ruby on Rails in a hot new technology that has gotten a good deal of media blather in the "Web 2.0" age and is just about as hyped as the term itself. It structures your coding. Something you can easily accomplish with Java, PHP, Perl, or any other language. The bigger issue is performance. ROR is just not at the same level of performance that PHP can accomplish, especially with Zend or eAccelerator type caches installed (latter is free and easily installed). It is much easier to find developers for PHP, and probably cheaper. The biggest site I have run, with about 25,000 visitors every hour at its peak, was based on a Movable Type (www.movabletype.org) platform with RightFields plugin. MovableTYpe itself is CGI, which I was not crazy about, but we grew to a traffic stage where we couldn't live with dynamic pages (however well designed) and MT gave us an excellent mix of static and dynamic (it spews out regular HTML pages). My point: it is easy to get caught up in this selection of technology. >From starting up several businesses, some with huge traffic, some not, here's my simple advice: LAPP makes a good chocie (Linux, Apache, PostgreSQL, PHP) as it is very cheaply available, is proven to work for many hugely successful sites, and is easy to find developers/experts for. What you should instead focus on is to build a website/service that will attract people. If your traffic proves to be a burden for your infrastructure, trust me, it'll be a lovely problem to have :) Erick
