nice site, few design comments:
1- the folder image (
http://www.scriptdownloads.com/images/folderpic.jpg) needs to be fixed, and it's background must be white.
2- Navigation menu height should be increased and the text should be enlarged to give the main script categories its presence on the page.Don't forget that you want the users to navigate through your site. So the bigger the main menu, the more likely they will click on its categories.
3- I would use some cliparts, or a different style of icons for the home | Directory | Register.... menu. The orange icons are nice for the categories, but they don't fit on the top, they are using too much height while the main menu should use that height.
4- To commercially benefit from the site, consider increasing the width of your content area and put a skyscrapper banner or 3-4 small 120*120 ads boxs. I would use a banner rotating script and subscribe to other advertising company in addition to Google Ads. Don't depend on one source of income when it comes to online ads. A nice idea would be to subscribe to multiple banner excahnge networks and use your banner rotator to rotate their ads. This way you will get free advertising to your site, and you will fillup the empty ad space till you start getting some good traffic that can generate money from ads.
5- Consider having a Books section for PHP, ASP, Perl, Java, C++ books(affilate with amazon.com). With such good targetted traffic, this should earn you a nice check every month.
Just my 2 cents. Good luck with this nice site ;-)