18 Portable Apps That Every Tech Needs � CaseyTech.com The subject says it all. Plus, in the comments, there are quite a few more apps named.
MooTools Help! I Don't Know JavaScript! This page contains a great listing of various reference sites, tutorials, etc for HTML, CSS, JavaScript, etc. If you are just getting started in coding, or wanting to bone up on the basics, you can't go wrong by starting here.
SWFs, like other documents and media retrieved by a Web browser, are often saved, or cached, locally on the user's hard drive. The next time that media is requested the Web browser may load the file from the cache instead of downloading it over the network. This might be desirable for a Flash movie whose content doesn't change often but undesirable for SWFs that are updated frequently with new content or information.
I forgot to mention that you will need Lightning in order to fully integrate the Mozilla calendar product with either Sunbird (a cross-platform calendar app) or Thunderbird (stand alone email application).