Open-source Wordtune alternatives

LanguageTool is open-source proofreading software that finds grammar and style errors a simple spell checker would miss. It supports English, Spanish, French, German, Portuguese, Polish, Dutch and more than 20 other languages. The core is written in Java and freely available under the LGPL 2.1 or later.

It can be used in several ways. The project documents how to run your own LanguageTool server, an HTTP API for sending text to a server, a public server that can be used over HTTP, and a Java API with Javadoc. Error detection works through rules, and the development overview explains how to contribute new rules for a language.

Community-contributed Docker files are listed for people who want to run a containerized server. Building from source needs Java 17 and Apache Maven, and the README offers a scripted install as well as a shallow clone option to reduce download size, since a complete clone is large. A forum is available for questions.

Writely is a browser extension that brings GPT-powered writing assistance to any text field on the web, rather than being limited to a single app like Notion. It is aimed at people who want AI help writing emails, articles or social media replies wherever they happen to be typing, without switching to a dedicated AI writing tool.

Built on OpenAI's GPT models, it offers a writing assistant usable on virtually any editor webpage, and it can also perform query translation and reading assistance to help users understand and respond to content faster. Example uses mentioned in the README include drafting emails, writing articles, replying to posts on platforms like Twitter and Weibo, and writing stories on Zhihu. After selecting text on a page, a small 'W' icon appears near the cursor that opens the assistant.

Writely is available for Chrome, Firefox and Edge, and requires the user to supply their own OpenAI API key, obtained from OpenAI's platform and entered into the extension's settings. It is written in TypeScript, currently in beta, and released under the MIT license, with a Discord community for users and contributors.