Lego Ideas (formerly known as Lego Cuusoo). Originally LEGO Cuusoo was a website run by Chaordix and LEGO. The website allowed users to submit ideas for LEGO sets. There would be a voting process, and if a set made it to 10,000 votes, the set would go into a review process, where it had the potential to be released. The original designer receiving 1% of the royalties. It started in 2008 as an offshoot of the Japanese website Cuusoo.
The Lego Ideas Shinkai 6500 Submarine holds the honour of being the first Lego Ideas set to be produced. In fact, it wasn’t even called Lego Ideas at the time, but Lego Cuusoo instead. This set was only released in Japan.
You can find the building instructions at the official LEGO site
