We’ve added an article on the Developer Portal that lists some great third party tools to help make development on webOS even easier. There’s a Mojo-specific TextMate bundle, plus some tools to help with localization. We’ve found these tools be be really useful, and we think you will too. Since these aren’t Palm products, we don’t support or guarantee these tools in any way – we just think they’re cool.
We’ll be adding to this list as we discover more tools. Please let us know if you see any you’d like included!