Omniorthogonal occasionally muses on the "cambrian explosion" of open source software. Damn straight.
The Open Source CMS site just stunned me. It includes live demos of all the major PHP/Apache/MySQL web software thingies: CMS'es, CRM's, blogs, Wiki's, etc.
The one that particularly caught my attention was SugarCRM. Not 10 years ago I worked for corporations that paid millions of dollars on combinations f buying, writing, and integrating what used to be called "Sales Automation" (now "Customer Relationship Management") systems like this. That's not even including the heavy-duty server hardware it had to run on. Even smaller-scalle tools like this were still really expensive, slow, and generally sucky.
And here's one for free, and overall way ahead of the ones we had to deal with. And the "hardware" to run it on can be rented for $1/GB of bandwidth. Astounding.