I'm asking myself "why am I here [on drupal.org]?" The reasons are purely philosophical.
Being new to internet technology (at least the guts of it), I think it may be worthwhile to step back and ask for help to understand the bigger picture of available choices.
I want to create web applications in addition to an interactive, dynamic website--unless I misunderstand and they are the same. I also would like help down the road by making my work an open source project (modules, etc.).
But I want to know whether I have any big misunderstandings about just what Drupal can or cannot ever help me do.
Based on my very limited understanding, these are conclusions I've come to. I'm thinking I need to use Apache (though a recent post on lighttpd got my attention). Strongly tempted to use FreeBSD. PHP seems a popular, feature-rich, and fast web scripting language, and I prefer it over perl, java, python, based on limited knowledge of them. I don't want to learn Java. A CMS seems a way to get functionality without having to program it myself. PEAR is available. Yahoo has used PHP for its web applications. I cannot evaluate whether to prefer an objected-oriented PHP or procedural PHP approach. I can supplement PHP and Apache with custom code programmed in C, when speed or security is necessary.
What I do not know is, what can PHP not do? What can companies/organizations with much financial resources do for their websites/web applications and is PHP a tool they would rely on? I ask that last question because, I hope my project will scale quickly and that its depth and complexity will also increase quickly, so I need to know if my basic conclusions will allow me to accomplish that. As you see, this isn't really a question about Drupal, per se, but just the category that Drupal fits in: a PHP CMS. I truly have an open mind, since I know so little.