Without Open Source there would be no WikiDot.com. For sure. It is not only a matter of $$$ - anyway, did you know that you can spend nothing on software and successfully develop advanced web applications? It is a matter of quality, openness, communication and standards.
And talking about the budget: did you know that the total cost of WikiDot.com development was less than $4000? This includes hardware & server costs, salaries, Internet connection etc. This would certainly not be the case without Open Source ;-)
Here we would like to mention main open source projects that have been used for WikiDot development.
One of the most advanced and feature-complete open source database with astonishing performance. PostgreSQL is used for all data storage (except files).
One of the most popular and advanced scripting languages for building web applications. No need to introduce ;-)
Apache HTTP Server
Top open source web server. Used to serve all WikiDot.com pages.
OZONE Web Application Framework
PHP PEAR & PECL
A lot of useful code. A few selected projects have been used here.
This is used as a core Wiki engine at WikiDot.com. But to be honest - almost 50% of the code has been changed to produce valid XHTML code. A lot of new rules and features has been added.
A great PHP template engine. It is used to render HTML layouts, build database object model files, generate emails.
Memcached is a high-performance, distributed memory object caching system originally developed by Danga for LiveJournal.com. We use it to cache database objects, compiled page conents, modules contents and whole pages for sessionless requests. Anyway - it increases performance of our servers even by 6000%.
eAccelerator is a PHP accelerator, optimizer, encoder and dynamic content cache. It is used as an Apache extension and caches compiled PHP code. Highly recommended!
Full-text-search engine for PostgreSQL. It is used to index both page contents and forum discussions.
Eclipse & PHPeclipse
Main IDE for the project. Eclipse is without question the most advanced open source IDE you could find. PHPeclipse is a plugin that can handle PHP projects.
The most popular open source browser powered by the Gecko engine. Used as a reference browser. Combined with a few useful extensions it is a great tool for web development.
Only Linux OS has been used for development (other OSs only for testing). And the favorite Linux distribution is Gentoo ;-)