All your programmers this is the place you must be. Great site to get info on which software to use for what.

http://ostatic.com/searchtag/all/project

My Work Experience with Open Source Technology

Famous Open Source:
http://wordpress.org - Blog
http://www.phpbb.com/ - Forum
http://memht.com - Portal
http://oscommerce.com - Ecommerce
http://www.sphider.eu - Search Engine PHP & MySQL
http://www.atomz.com/ - Search Engine free & paid - awesome
http://www.keyoti.com/ - Dotnet Search Engine paid one - awesome

Other:

SEO:
http://www.google.com/cse/ - Google Custom Search Engine
http://www.google.com/analytics/ - Google Analytics
https://www.google.com/adsense/support/bin/answer.py?answer=81558 - Google Adsense

Bug tracking tool:
http://www.mantisbt.org/ its like bugzilla tool.

Email Blasting Tool:
http://www.icontact.com/ - Bulk Email blastinc tool - awsome functions

Gallery :
http://coppermine-gallery.net/

Payment Gateway:
ICICI payseal Integration
Paypal

Famous Captcha:
http://recaptcha.net/


Famous Useful Sites:
1. https://login.salesforce.com/ - External secure Database purpose
2. http://www.snap.com/ - snap shots
3. http://youtube.com
4. http://www.cbox.ws/
5. http://www.enote.com/
6. http://www.allgraphicstools.com/free.htm - Color picker awesome
7. http://www.hiteksoftware.com/ - ableFTP software (Secure Automated scheduling software) paid but very useful

PHP, MySQL - Search Engine

Awesome - PHP, MySQL - Open Source - Search Engine

http://www.sphider.eu

HTTP Authentication With PHP & htpasswd

Check this out, brilliant work:

http://koivi.com/php-http-auth/