Not sure if it's in the same bucket as Valve or GitHub: at Mobile Jazz
http://mobilejazz.com we're only 20 people (and that makes things a lot easier), but we've quite a different way of working compared to traditional companies:
* We pay fair salaries. For most people in our team it's way more than what they've earned before.
* We pay everyone the same (base) salary. Regardless of their role or title.
* We pay quarterly bonuses based on pro-activity, responsibility and other performance indicators.
* Everyone can work from wherever they like, still many people choose to work from our main office in Barcelona. (For example I work many weeks out of my camper van with 3G/4G connection from beautiful surf locations)
* In theory, everyone can choose how much or how little they want. Not always possible, but we try to make it possible as much as we can.
* We have managers, but they don't demand things. They are responsible that certain things happen, but decisions are being made collaboratively.
* All managers are either engineers or designers. No bullshit managers.
* We don't have a dedicated sales person. All work we get is from word-of-mouth and the first person a new client speaks to is either an engineer or designer (or both).
* We play Mario Kart / StarCraft after lunch ;-)
* We do a lot of sports activities together
* We have a lot of BBQs on our terrace
* We use some of the profits for fun internal experiments
(small projects without an expected outcome other than having fun & learning). However, some of them are now actually turning into actual products: http://bugfender.com/
* MJ University: we take online classes together as a group
* MJ Talk: weekly presentation about an interesting topic (not necessarily tech related). For example we had talks about personal finance (investing), achieving happiness, etc.
* We encourage pair programming where it makes sense
* MJ Weekend: once or twice every year we fly everyone to Spain, rent a nice villa with pool and have a good time together. Some pics: http://blog.mobilejazz.cat/work-life-balance-at-mobile-jazz/
* MJ Retreats: we're going to remote places and work there together. At the moment six of us are on an island in Thailand. In February we go skiing in Austria.
* We put a lot of effort in hearing everyone's opinion and feedback and try to put it into action
With all that we've managed to attract and retain incredible talent, but most importantly we have a very pleasant time together.
That said, we're a company optimizing on lifestyle and happiness, rather than profit. So this way of running a business is probably not applicable everywhere.
(Edit: formatting, typos and a few additions)