Magpul announced their free licensed mounting system M-LOK. This is a mounting system that is a direct attachment method for hard mounting accessories to a negative space mounting point.
This is billed as the evolution of MOE system and has following features.
• DIRECT MOUNT CAPABILITY
• CAMMED T-NUT
• OPTIMIZED FOR METAL AND POLYMER MANUFACTURING
• RECOIL/IMPACT MITIGATION LUGS
• INTERMEDIATE SPACING OPTION
• MULTI-DIRECTIONAL MOUNTING
• BACKWARDS MOE COMPATIBILITY
MOE accessories can be used for M-LOK with adapter plates, but not the other way around.
You can read more about the system from:
http://magpul.commercev3.com/downloads/M-LOK_Release_FAQs.pdf
From: Soldier Systems, Magpul