Question: I'm looking for a grammar and spell checker that can be deployed on-premise for high security requirements.

If you need a powerful grammar and spell checker that you can run on-premise for maximum security, WProofreader is a good choice. The AI-powered suite of tools works with more than 20 languages and includes multilingual sentence checking, AI paraphrasing, and strong security features like TLS encryption and GDPR compliance. It can be run in a variety of ways, including on-premise and in the cloud, so it's adaptable.

Another good option is GrammarBot, an offline AI-powered app that checks grammar and spelling even without a network connection or subscription. It downloads a local large language model (LLM) and works like a personal version of ChatGPT, keeping your data private on your machine. It only works on macOS for now, but Windows and Linux support is planned.

For those who need a platform that can handle heavy-duty processing and data sovereignty, Prem could be a good choice. It lets companies use personalized LLMs and can be run on-premise, which is important for sensitive data. The platform can handle custom prompts and fine-tuning, which makes it a good option for companies that want to train AI models to their own specifications.

If you want to embed a grammar and spell checker into your own system, CKEditor could be useful. It's a JavaScript-based text editor that offers advanced features like collaborative real-time editing, AI-assisted writing and customizable proofreading. It can be integrated with common frameworks and supports multiple languages, making it a good tool for a variety of content creation tasks.