Analysis of information sources in references of the Wikipedia article "Google Native Client" in English language version.
As a replacement, Google is now pushing WebAssembly.
PNaCl sandboxes allow game-play developers to use modern C++ and C/C++ libraries directly within their virtual machines and will allow for better code sharing between the engine code and game logic. PNaCl is also reported to offer better performance than the original Quake III virtual machines.
They've continued moving along with their open-source game and Daemon engine. […] their libRocket implementation has moved into the NaCl VM.
Open-source Unvanquished developers continue working on support for using Google's Portable Native Client (PNaCl) to replace Quake III QVMs.
Under the hood, they remain hard at work on porting the game logic from QVMs to Portable Native Client (PNaCl).