Cleveland's Blockparty returns this April 15th-18th alongside hacker conference Notacon, now in its fourth year running (out of five promised annual editions) -- making this the longest running demoparty in North America to date. To prepare for the show, organizers have set up a Block Party 2010 site with details on the event.

For those of you still unfamiliar with the demoparty concept, Blockparty 2010's organizers break it down: "set up a stage, invite programmers, artists and musicians from around the world to enter competitions, watch in amazement what comes out, and then hand out prizes to the best of the bunch."

As with previous shows, Blockparty 2010 will feature competitions like demo, HiRez, textmode, music, photography, wildcard (generally animated short films or short visual productions) and more. Returning attendees will want to check out the site for info on the new competition machine, rules, and category changes.

The show will also have seminars and presentations like Guybrush's "Proce55ed Synaesthesia for fun and profit". You can find information on registering for Notacon 7 and Blockparty 2010 (around 135 out of 400 tickets are already sold as of this posting) at the Notacon site.