SwiftLaTeX, a WYSIWYG Browser-based LaTeX Editor

SwiftLaTeX (Actively developing)

One-liner introduction for SwiftLaTeX

SwiftLaTeX, a WYSIWYG WebAssembly-powered LaTeX Editor.

What are the differences to Overleaf or ShareLaTeX?

1. Speed. SwiftLaTeX engines run in browsers. It makes SwiftLaTeX more responsive (i.e., faster compilation) and scalable.

2. WYSIWYG. SwiftLaTeX provides a WYSIWYG viewer, allowing users to editing PDF output directly.

3. VS Code. SwiftLaTeX is built atop the famous VS code platform, supporting rich editing features like LaTeX language server (i.e., code completion and syntax highlighting), spell check, and live preview.

4. Flexible Storage Backend. SwiftLaTeX stores files in self-hosting Minio Object storage. SwiftLaTeX can also sync project files to different cloud storage backends such as Dropbox, Google Drive, OneDrive, and Github.

5. Realtime collaboration. Send a secret link to your friend to start real-time collaboration.

Great, I wanna have a try!

Try it in https://v2.swiftlatex.com

Or host it by yourself using docker-compose

git clone https://github.com/SwiftLaTeX/SwiftLaTeX
cd SwiftLaTeX
docker-compose up

SwiftLaTeX Architecture

This section is devoted for interesting developers only. If you want more help, you could considering opening an issue.

SwiftLaTeX consists of three major components.

Engine

SwiftLaTeX engine (a C++ reimplementation of XeTeX) supports UTF-8 and Opentype fonts out of box. The engine binary exposes two major APIs _compileLaTeX and _compileBibtex. You may find the following source file useful as it showcases how to use these APIs. (https://github.com/SwiftLaTeX/IDE/blob/master/packages/latex/src/browser/latex-engine.ts).

The engine is not a faithful reimplementation of XeTeX. First, it does not support Chinese/Japanese/Korea/Arabic languages. Supporting these languages require a fully working ICU library, whose size may be unbearable. Secondly, the engine uses browsers' APIs to handle image files. Due to API limitation (or my laziness), our engine does not support multi-page PDF images yet. If you want to include a multi-page PDF images in your document, consider extracting the page you want to include and save it as an independent file first. (Todo, more details)

Currently, we have no plan to release the source code. Nevertheless, our team is happy to grant permission for you or your organization to use the binary for non-commercial purposes (e.g., individual or tertiary education). If you need more tech support on the engine or want to submit a feature request, you can contact g.weber(at)auckland.ac.nz.

Live Viewer

The live viewer converts the output of the Engine (DVI format) to HTML, so it can be displayed in a browser more efficiently (rather than relying on PDF.js). You may find the following two files useful.

1. DVI parser (https://github.com/SwiftLaTeX/IDE/blob/master/packages/latex/src/browser/xdv-parser.ts).
2. HTML generator (https://github.com/SwiftLaTeX/IDE/blob/master/packages/latex/src/browser/xdv-machine.ts)

The generated HTMLs contains synchronization information (similar to SyncTeX), which is the mapping from the HTML element to the source code position. The information has a character-grained accuracy, which then allows us to implement WYSIWYG editing on the viewer.

However, SwiftLaTeX is a quick evolving project and the viewer may consist of a small number of bugs. We are currently working hard on the following issues. We expect to fix them in the next few weeks.

1. Previewer may fail to display certain documents. (e.g., \usepackage{2up} will screw the viewer)

2. Previewer may fail to display images.

3. WYSIWYG functionality is not available for formulas yet.

VS Code (Theia)

Theia is a fork of VS code and designed to have high extensibility. SwiftLaTeX extends Theia in following aspects.

1. S3 Storage. SwiftLaTeX stores users files in self-hosting Minio server or public Amazon S3 cloud. To do that, we rewrote the filesystem subsystem of Theia. (https://github.com/SwiftLaTeX/IDE/blob/master/packages/filesystem/src/browser/s3storagesystem.ts.) Optionally, we also provide a backend service to sync the files to different cloud storage like Google, Dropbox, and Github.

2. Realtime Collaboration We extends the Monaco Editor of Theia to support realtime collaboration among different users. (https://github.com/SwiftLaTeX/IDE/blob/master/packages/latex/src/browser/monaco-yjs.ts). The collaboration uses CRDT implementation, more details can be found at https://github.com/yjs/yjs.

3. Language Server We incorporate a TeXLab language server (https://github.com/SwiftLaTeX/texlab-swiftlatex), which provides auto-completion, syntax highlighting, and API documents supports. The language server has been modified to support multiple users. [Todo: more details]

Note that, we only include the generated binary in this repo. To hack the IDE, please checkout (https://github.com/SwiftLaTeX/IDE)

License

SwiftLaTeX is released under AGPL3 license.