Open Source Language Servers
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Language Servers
View 1473 business solutionsBrowse free open source Language Servers and projects for Windows and Mac below. Use the toggles on the left to filter open source Language Servers by OS, license, language, programming language, and project status.
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clangd
clangd language server
clangd understands your C++ code and adds smart features to your editor: code completion, compile errors, definition, and more. clangd is a language server that can work with many editors via a plugin. Here’s Visual Studio Code with the clangd plugin, demonstrating code completion. -
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GraphQL
The GraphQL LSP reference ecosystem for building browser & IDE tools
GraphiQL is the reference implementation of this monorepo, GraphQL IDE, an official project under the GraphQL Foundation. The code uses the permissive MIT license. Whether you want a simple GraphiQL IDE instance for your server, or a more advanced web or desktop GraphQL IDE experience for your framework or plugin, or you want to build an IDE extension or plugin, you've come to the right place! GraphiQL provides monaco editor with a powerful, schema-driven graphql language mode. It also provides CodeMirror with a parser mode for GraphQL along with a live linter and typeahead hinter powered by your GraphQL Schema. It comes with a runtime agnostic Language Service used by GraphQL mode for CodeMirror and GraphQL Language Service Server. It also provides an online immutable parser for GraphQL, designed to be used as part of syntax-highlighting and code intelligence tools such as for the GraphQL Language Service and codemirror-graphql. -
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lua-language-server
A language server that offers Lua language support - programmed in Lua
The Lua language server provides various language features for Lua to make development easier and faster. With around half a million installs on Visual Studio Code, it is the most popular extension for Lua language support. The language server can be installed for use in Visual Studio Code, NeoVim, and any other clients that support the Language Server Protocol. The language server can be configured using a configuration file. The language server and Visual Studio Code client can be installed from the VS Code Marketplace. Check the wiki for a guide to install the language server for use on the command line. This allows the language server to be used with other clients that follow the language server protocol. -
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ccls
C/C++/ObjC language server supporting cross references & hierarchies
C/C++/ObjC language server supporting cross-references, hierarchies, completion, and semantic highlighting. It has a global view of the code base and supports a lot of cross-reference features, see wiki/FAQ. It starts indexing the whole project (including subprojects if exist) parallelly when you open the first file, while the main thread can serve requests before the indexing is complete. Saving files will incrementally update the index. Hierarchies, call (caller/callee) hierarchy, inheritance (base/derived) hierarchy, member hierarchy. Symbol rename. Document symbols and approximate search of workspace symbol. Hover information. Diagnostics and code actions (clang FixIts). Semantic highlighting and preprocessor skipped regions. -
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Eclipse Che
Next-gen container development platform, workspace server & cloud IDE
Eclipse Che is a Kubernetes-native IDE that makes Kubernetes development accessible for development teams. It places everything a developer could need into containers in Kube pods including dependencies, embedded containerized runtimes, a web IDE, and project code. With the Kubernetes application in your development environment and an in-browser IDE, you can code, build, test and run applications exactly as they run on production from any machine. -
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JupyterLab LSP
Coding assistance for JupyterLab (code navigation + hover suggestions
Hover over any piece of code; if an underline appears, you can press Ctrl to get a tooltip with function/class signature, module documentation or any other piece of information that the language server provides. Critical errors have red underline, warnings are orange, etc. Hover over the underlined code to see a more detailed message. Use the context menu entry, or Alt + 🖱️ to jump to definitions/references (you can change it to Ctrl/⌘ in settings); use Alt + o to jump back. Place your cursor on a variable, function, etc and all the usages will be highlighted. When a kernel is available the suggestions from the kernel (such as keys of a dict and columns of a DataFrame) are merged with the suggestions from the Language Server (in notebook). If the kernel is too slow to respond promptly only the Language Server suggestions will be shown (default threshold: 0.6s). You can configure the completer to not attempt to fetch the kernel completions if the kernel is busy. -
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Psalm
A static analysis tool for finding errors in PHP applications
It’s easy to make great things in PHP, but bugs can creep in just as easily. Psalm is a free & open-source static analysis tool that helps you identify problems in your code, so you can sleep a little better. Psalm helps people maintain a wide variety of codebases, large and small, ancient and modern. On its strictest setting it can help you prevent almost all type-related runtime errors, and enables you to take advantage of safe coding patterns popular in other languages. Psalm also fixes bugs automatically, allowing you to improve your code without breaking a sweat. If Psalm cannot infer a type for an expression then it uses a mixed placeholder type. mixed types can sometimes mask bugs, so keeping track of them helps you avoid a number of common pitfalls. Psalm has a Language Server that’s compatible with a range of different IDEs. Psalm can fix many of the issues it finds automatically. -
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csharp-ls
Roslyn-based LSP language server for C#
This is a hacky Roslyn-based LSP server for C#, as an alternative to omnisharp-roslyn. csharp-ls requires .NET 7 SDK to be installed. However, it has been reported to work with projects using older versions of dotnet SDK, including .NET Core 3, .NET Framework 4.8 and possibly older ones too as it uses the standard Roslyn/MSBuild libs that Visual Studio & omnisharp does. csharp-ls implements the standard LSP protocol to interact with your editor. However there are some features that need a non-standard implementation and this is where editor-specific plugins can be helpful. Supports automatic installation, go-to-metatada (can view code from nuget/compiled dlls) and some additional features. -
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rust-analyzer
A Rust compiler front-end for IDEs
rust-analyzer is a modular compiler frontend for the Rust language. It is a part of a larger rls-2.0 effort to create excellent IDE support for Rust. If you want to contribute to rust-analyzer or are just curious about how things work under the hood, check the ./docs/dev folder. If you want to use rust-analyzer's language server with your editor of choice, check the manual folder. It also contains some tips & tricks to help you be more productive when using rust-analyzer. rust-analyzer is an implementation of Language Server Protocol for the Rust programming language. It provides features like completion and goto definition for many code editors, including VS Code, Emacs and Vim. For VS Code, install rust-analyzer extension from the marketplace. Prebuilt language server binaries for Windows, Linux and Mac are available on the releases page. -
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Elixir Language Server
A frontend-independent IDE "smartness" server for Elixir
Implementing features such as auto-complete or go-to-definition for a programming language is not trivial. Traditionally, this work had to be repeated for each development tool and it required a mix of expertise in both the targeted programming language and the programming language internally used by the development tool of choice. The Elixir Language Server (ElixirLS) provides a server that runs in the background, providing IDEs, editors, and other tools with information about Elixir Mix projects. It adheres to the LSP, a standard for frontend-independent IDE support. Debugger integration is accomplished through a similar VS Code Debug Protocol. These pages contain all the information needed to configure your favorite text editor or IDE and to work with the ElixirLS. You will also find instructions on how to configure the server to recognize the structure of your projects and to troubleshoot your installation when things do not work as expected. -
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Jsonnet Language Server
A Language Server Protocol (LSP) server for Jsonnet
A Language Server Protocol (LSP) server for Jsonnet. The design is influenced by several configuration languages internal to Google, and embodies years of experience configuring some of the world's most complex IT systems. Jsonnet is now used by many companies and projects. -
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Metals
Scala language server with rich IDE features
Scala language server with rich IDE features. -
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Python LSP Server
Fork of the python-language-server project
Fork of the python-language-server project, maintained by the Spyder IDE team and the community. A Python 3.7+ implementation of the Language Server Protocol. The base language server requires Jedi to provide Completions, Definitions, Hover, References, Signature Help, and Symbols. Like all language servers, the configuration can be passed from the client that talks to this server (i.e. your editor/IDE or another tool that has the same purpose). The details of how this is done depend on the editor or plugin that you are using to communicate with python-lsp-server. The configuration options are available at that level are documented in CONFIGURATION.md. Overall configuration is computed first from user configuration (in home directory), overridden by configuration passed in by the language client, and then overridden by configuration discovered in the workspace. -
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crystalline
A Language Server Protocol implementation for Crystal
Crystalline is an implementation of the Language Server Protocol written in and for the Crystal Language. It aims to provide limited language features (like go-to, autocompletion, syntax and semantic checking) and ease development with any compatible code editor. Crystalline is not as extensive in terms of features as other Language Servers but still provides very convenient tools. Code Diagnostics. Syntax and semantic checks on save. Limited Autocompletion. List (depending on the target) method definitions, macros or module/class/struct names or symbols available in the current context. A whole document or a text selection. By clicking on a symbol with the Cmd or Ctrl key pressed (editor/platform dependent). Hovering should display (when possible) either a variable type, a function definition signature or the expanded macro. -
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ALE
Check syntax in Vim/Neovim asynchronously and fix files
ALE is an asynchronous linting and fixing engine for Vim and Neovim that keeps feedback flowing without blocking your editor. It runs external linters and formatters in the background as you type or save, streaming diagnostics into the sign column and statusline. The project focuses on breadth and practicality: dozens of languages work out of the box, and configuration is usually a matter of selecting tools you already use on the command line. ALE can also act as a lightweight Language Server Protocol client, providing go-to-definition, hover, and code actions through LSP servers when available. Its fix-on-save pipelines and formatter integration help enforce team style guides reliably and repeatably. For large codebases and slower linters, ALE’s job queueing and smart debouncing prevent UI hiccups while still surfacing timely results. -
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Ansible Language Server
Ansible Language Server
This language server adds support for Ansible. Ansible keywords, module names and module options, as well as standard YAML elements are recognized and highlighted distinctly. Jinja expressions are supported too, also those in Ansible conditionals (when, failed_when, changed_when, check_mode), which are not placed in double curly braces. While you type, the syntax of your Ansible scripts is verified and any feedback is provided instantaneously. On opening and saving a document, ansible-lint is executed in the background and any findings are presented as errors. -
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Astro Language Tools
Language tools for Astro
This repository contains all the editor tooling required for the Astro language (.astro files). Notably, it contains an implementation of the Language Server Protocol (LSP) which as of now is used for the official VSCode Extension but could also be used to power a plugin for your favorite IDE in the future. This repository is a monorepo managed through Turbo, which means that multiple packages are in this same repo (packages folder). The official VS Code extension for Astro. This enables all of the editing features you depend on in VSCode for .astro files. -
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D Language Server
A Language Server implementation for D
This is still a work in progress; there might still be bugs and crashes. DLS implements the server side of the Language Server Protocol (LSP) for the D programming language. It doesn't do much itself (yet), and rather uses already available components, and provides an interface to work with the LSP. DLS is usable using FreeBSD's Linux binary compatibility system (tested on FreeBSD 12.0-RELEASE). Code completion, going to the symbol definition, finding references, symbol renaming. Error checking, code formatting (document, range and on-type), symbol listing (current document and workspace-wide). Symbol highlighting, documentation on hover, random, frustrating crashes. -
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Eclipse GLSP
Graphical language server platform for building web-based diagram
The Graphical Language Server Platform (GLSP) is an extensible open-source framework for building custom diagram editors based on web technologies. Alongside an extensible client framework and a server framework, GLSP provides a language server protocol (LSP) for diagrams. With that, GLSP enables the development of modern, web-based diagram editors, whereas the heavy lifting, such as loading, interpreting, and editing according to the rules of the modeling language, is encapsulated in the server. GLSP provides integration layers, to use GLSP editors seamlessly in web pages, Eclipse Theia, VS Code and even Eclipse desktop. GLSP provides the perfect basis for the efficient development of web-based diagram editors including edit functionality, layouting, shapes, palettes and everything else you expect from a powerful, modern diagram editor. GLSP doesn't hide the underlying rendering technologies, such as Eclipse Sprotty, SVG, and CSS. -
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Elm Plugin for Visual Studio Code
Improving your Elm experience since 2019
Errors and pieces of information when changing code and when saving (Control + S) Format on save (Control + S) (Make sure you also enable the "Editor: Format on Save" setting for this to work). Suggests completions and snippets (Control + Space) Test explorer integration. Lists all references to a type alias, module, custom type or function (Alt + Shift + F12) Jump to the definition of a type alias, module, custom type or function. Shows type annotations and documentation on hover for type alias, module, custom type or function. Rename a type alias, module, custom type or function (F2) Browse file by symbols (Control + Shift + O). Browse the workspace by symbols (Control + Shift + R) Codelenses show how many times you call a function and if it's exposed or not. -
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Haskell IDE Engine (HIE)
The engine for haskell ide-integration. Not an IDE
This project aims to be the universal interface to a growing number of Haskell tools, providing a fully-featured Language Server Protocol server for editors and IDEs that require Haskell-specific functionality. Supports plain GHC projects, cabal projects(sandboxed and non sandboxed) and stack projects. Fast due to caching of compile info. Uses LSP, so should be easy to integrate with a wide selection of editors. Diagnostics via hlint and GHC warnings/errors. Code actions and quick fixes via apply-refact. Type information and documentation(via haddock) on hover. Jump to definition. -
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This is a new generation of SQL (Structured query language) Server which is targeted to serve on a Virtual Appliance. Hybrid SQL Server is targeted to run on VirtualBox from SunMicrosystems.
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LSP-AI
LSP-AI is an open-source language server
LSP-AI is an open source language server that serves as a backend for AI-powered functionality in your favorite code editors. It offers features like in-editor chatting with LLMs and code completions. Because it is a language server, it works with any editor that has LSP support. -
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LTEX LS
LTeX Language Server: LSP language server for LanguageTool
LTEX LS (LTEX Language Server) implements a language server according to the Language Server Protocol (LSP) and provides grammar and spelling errors in markup documents (LATEX, Markdown, etc.). The documents are checked with LanguageTool. Typically, you start the language server (either locally or remotely), you send the language server your LATEX or Markdown document, and it will respond with a list of the grammar and spelling errors in it. To use LTEX LS in this way, you have to use a language client (usually an editor or an extension of the editor) that communicates with LTEX LS according to the LSP. However, it is also possible to supply LTEX LS paths to files and directories to be checked as command-line arguments. In this mode, LTEX LS will print the results to standard output, and no language client is necessary. -
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Language Server Protocol for Emacs
Emacs client/library for the language server protocol
Client for Language Server Protocol (v3.14). lsp-mode aims to provide IDE-like experience by providing optional integration with the most popular Emacs packages like company, flycheck and projectile. Works out of the box and automatically upgrades if additional packages are present. Choose between full-blown IDE with flashy UI or minimal distraction-free. Supports all features in Language Server Protocol v3.14. Semantic tokens as defined by LSP 3.16 (compatible language servers include recent development builds of clangd and rust-analyzer). If LSP server supports completion, lsp-mode use symbols returned by the server to present the user when completion is triggered via completion-at-point. For UI feedback of the available code actions, you can enable lsp-modeline-code-actions-mode which shows available code actions on modeline.
