Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
LibHunt - LibHunt tracks mentions of software libraries on relevant social networks. Based on that data, you can find the most popular projects and their alternatives.
Cvent - Cvent's event management software provides event planners with a complete solution to increase event attendance and decrease event costs.
AlternativeTo - AlternativeTo lets you find apps and software for Windows, Mac, Linux, iPhone, iPad, Android, Android Tablets, Web Apps, Online, Windows Tablets and more by recommending alternatives to apps you already know.
Ticket Tailor - Ticket Tailor is an easy-to-use event ticketing platform that allows event organizers of all shapes and sizes to sell tickets online.
JSter - JSter is a community-driven catalog of the most useful javascript libraries.