Eclipse Theia is an open-source IDE and IDE platform for cloud and desktop, built as its own codebase rather than as a fork of VS Code. The Theia IDE product includes Theia AI, the AI layer that lets you choose which language models are used: cloud models, self-hosted OpenAI-compatible services or local models through, for example, Ollama and Llamafile. Prompts and agents can be customised as well. It is an alternative to VS Code with GitHub Copilot and other AI development environments, and as a platform it can be used to build a tailored IDE of your own.
Theia is a project of the Eclipse Foundation, an independent non-profit organisation based in Brussels (Belgium), with vendor-neutral governance. The software is licensed under the Eclipse Public License 2.0 and you run it yourself, on your own systems or in your own cloud environment. Chat sessions are stored locally in your user home directory. Where prompts go depends on the model you configure; with a local or self-hosted model, nothing needs to reach an external provider.