Igalia is a quite specific "consulting" agency that employs developers and get contracts from client to implement specific features or fix specific bugs, usually around FOSS. They have people who knows how to contribute to Firefox, Chrome, WebKit, Linux, Mesa... It's the go to company if you want to get something done in these projects when not having the resources for that in house.
For example they work for Valve to make the Radeon drivers better and got a grant to get basic MathML support done in the three major web browsers.
For example they work for Valve to make the Radeon drivers better and got a grant to get basic MathML support done in the three major web browsers.