The man responsible for Xbox Live is leaving Microsoft.

Boyd Multerer is no longer at the Xbox’s parent company (via Neowin). The engineer posted a “goodbye” this morning, saying that it was time for him to look into doing something new. This comes after 18 years with Microsoft. During that time, Multerer launched the Xbox Live online networking service and created the XNA game-development language.

As director of development for Microsoft’s Xbox division, Multerer was most recently responsible for helping to design the Xbox One. He was key to giving Microsoft’s latest gaming hardware three different operating systems to let it quickly jump between games, apps, and the menu system.

Multerer said he recognized the changing needs of the gamer were in conflict with the needs of the developers, and his designs for the Xbox One reflected that.

“[Developers] want to know exactly how much RAM they can use, and exactly how much CPU, and exactly how the graphics are going to work, and that should never change,” Multerer said in an interview on Microsoft’s new site from 2013. “The needs of the gamer and the needs of the game developers are at direct odds, so how do you serve both at the same time? That’s the real reason why we did two separate operating systems. One is more static, aimed letting game developers ability to deliver the best games, and one is aimed at the gamer to give them an evolving, changing, updating console that will be able to support the next big social network that hasn’t even been invented yet.”

Prior to the Xbox One, Multerer’s impact on the Xbox platform was huge. The Xbox Live he created for the original Xbox system is still the backbone of the online infrastructure the Xbox One uses today. The network was one of the first reliable online services for a console, and it made online gaming a requirement for all future systems from Sony, Nintendo, or Microsoft.

Multerer is also responsible for jumpstarting smaller independent games on Xbox 360 with his XNA tools. This software enabled people to make lightweight games that could run on a number of Microsoft platforms without needing to go through a tough porting process. People who built XNA games could even release them for sale on the Xbox Live Indie Games portal in the Xbox Live store. A number of studios that now make indie games for Xbox One, PlayStation 4, and Wii U got their start with XNA.

The Xbox Live and XNA mastermind has not said what he plans on doing next, but he did say that he is already writing code and experimenting with new ideas.

As for his legacy with Microsoft, he tweeted the following:

https://twitter.com/BoydMulterer/status/549590439758921730