The Foundry is absolutely kicking everyone else's ass with Nuke. They have an interesting business model as well: don't do much research in house, instead work

The Foundry is absolutely kicking everyone else's ass with Nuke. They have an interesting business model as well: don't do much research in house, instead work with studios with big R&D budgets and license their tools when they're mature, bringing it to a wider audience. They've done it with Digital Domain and Nuke (compositing), Weta and Mari (3d paint), and now Sony and Katana (lighting).