Best AI IDEs in Japan

The Windsurf Editor is a free AI-powered IDE and AI coding assistant that accelerates development by providing intelligent code generation and agents in over 70 programming languages and more than 40 IDEs, including VSCode, JetBrains, and Jupyter Notebooks. With Windsurf, developers can write code faster, eliminate repetitive tasks, and stay in the flow state—whether they're working with Python, JavaScript, C++, or any other language. Built on billions of lines of open-source code, Windsurf Editor understands and anticipates your coding needs, offering multiline suggestions, automated unit tests, and even natural language explanations for complex functions. It’s perfect for streamlining code writing, reducing boilerplate, and cutting down the time spent on documentation searches. Trusted by individual developers and Fortune 500 companies alike, Windsurf Editor is your go-to solution for boosting productivity and writing better code. Try Windsurf for free today!

Fast & powerful, cross-platform .NET IDE, develop .NET, ASP.NET, .NET Core, Xamarin or Unity applications on Windows, Mac, Linux. JetBrains Rider is a cross-platform .NET IDE based on the IntelliJ platform and ReSharper. Rider supports .NET Framework, the new cross-platform .NET Core, and Mono based projects. This lets you develop a wide range of applications including .NET desktop applications, services and libraries, Unity games, Xamarin apps, ASP.NET, and ASP.NET Core web applications. Rider provides 2200+ live code inspections, hundreds of context actions and refactorings brought by ReSharper, and combines them with the IntelliJ platform's solid IDE features. Despite a heavy feature set, Rider is designed to be fast and responsive. As well as running and debugging multiple runtimes, Rider itself runs on multiple platforms, Windows, macOS, and Linux. Most of ReSharper's 60+ refactorings are already available in Rider, and its 450+ context actions are all there.

Fine is an AI-powered development platform designed to assist startups by automating tasks throughout the software development lifecycle. It offers a range of AI agent workflows for coding, debugging, testing, and code review, allowing teams to ship daily improvements and resolve pull requests faster. Fine can autonomously create and implement code, conduct pull request reviews, generate tests, and handle common issues without constant human input. The platform integrates seamlessly with GitHub and supports asynchronous work, making it particularly suitable for fast-paced startups. With real-time feedback and live previews, Fine improves productivity and streamlines the development process.

Eclipse Theia is an extensible platform to develop multi-language Cloud & Desktop IDEs with state-of-the-art web technologies. Not sure whether you need a web or desktop version or both? With Theia you can develop one IDE and run it in browsers or native desktop application from a single source. The Theia project is hosted at the Eclipse Foundation, a not-for-profit corporation, and is developed by a diverse community. Unlike other "open-source" projects, projects hosted at an Open-Source Foundation are protected against single-vendor decisions against the interest of the diverse community. Theia is designed in a modular way to allow extenders and adopters customizing and extending every aspect of it. Composing a custom IDE-like product is as easy as listing all needed extensions in a package.json file. Adding new functionality by implementing your own extensions is easy, too and provides all the flexibility you need.

Agentforce Vibes introduces vibe coding, a generative AI–powered approach that lets developers convert natural language instructions into production-ready Salesforce applications with enterprise-grade security, governance, and infrastructure. Unlike simpler vibe coding tools aimed at prototyping, Agentforce Vibes supports the full development lifecycle, ideation, building, testing, deployment, and observability, while integrating with Salesforce’s platform and trust layers. It functions as an AI-powered IDE (usable within VS Code or any VS Code-compatible environment) that understands your Salesforce schema and metadata, enabling features such as agentic code generation (Apex, HTML, CSS, JavaScript), intelligent rule enforcement, test case generation, debugging, rollbacks, and natural language DevOps. It supports multiple language models, is extensible via Model Context Protocol (MCP) with over 20 built-in tools, and allows reuse of existing code.