C++

Scott Meyers has a new article up on his blog on the distinction between std::move and std::forward and their use in move constructors.

Bit Twiddling hacks is a great and pretty long compilation of trickery with regards to manipulating bits directly.

ChaiScript is an ECMAScript/JavaScript-inspired scripting language for embedding in C++ programs.

ViennaCL is an open source C++ computing library for scientific computing (mostly for solving linear systems) with multiple backends for CUDA, OpenCL, and OpenMP.

Andrey Sinyakov posted some great, introductory slides on new C++11 features. It's a pretty good whirlwind tour of the new standard.

Maths

Making Things with Maths is a fantastic, dynamic HTML5 slide set on using mathematics to procedurally create cool stuff. This is a truly awesome set of slides. Highly recommended!

Iñigo Quilez, of demoscene fame but now working at Pixar, gives some insights into the procedurally generated moss in the Pixar movie Brave.

The Nature of Code by Daniel Shiffman is an excellent resource to learn about the mathematical principles often found in nature. It uses Processing.js and contains lots of cool dynamic and interactive demos.

This page on Rapidly-exploring Random Trees is a great resource on an interesting algorithm to explore paths in nonconvex high-dimensional spaces. Pretty interesting technique. I found this via a reference from Casey Muratori's post in his post on The Witness blog on Mapping the Island's Walkable Surfaces.

Graphics

Sean Barrett wrote a great article on Corners Don't Look Like That: Regarding Screenspace Ambient Occlusion. I think we should move past SSAO as an industry. Unfortunately, I don't really see yet how we can replace it except for with expensive options like voxel cone tracing that might not be feasible for all games on next-gen consoles.

Here's a cool deferred area lights demo implemented in WebGL/three.js. It's based on an older post on the gamedev.net forums.