See [benchmark details](https://github.com/lightpanda-io/demo).
## Why?
### Javascript execution is mandatory for the modern web
Back in the good old times, grabbing a webpage was as easy as making an HTTP request, cURL-like. It’s not possible anymore, because Javascript is everywhere, like it or not:
- Ajax, Single Page App, Infinite loading, “click to display”, instant search, etc.
- JS web frameworks: React, Vue, Angular & others
### Chrome is not the right tool
So if we need Javascript, why not use a real web browser. Let’s take a huge desktop application, hack it, and run it on the server, right? Hundreds of instance of Chrome if you use it at scale. Are you sure it’s such a good idea?
- Heavy on RAM and CPU, expensive to run
- Hard to package, deploy and maintain at scale
- Bloated, lots of features are not useful in headless usage
### Lightpanda is built for performance
If we want both Javascript and performance, for a real headless browser, we need to start from scratch. Not yet another iteration of Chromium, really from a blank page. Crazy right? But that’s we did:
- Not based on Chromium, Blink or WebKit
- Low-level system programming language (Zig) with optimisations in mind
- Opinionated, no rendering
## Status
Lightpanda is still a work in progress and is currently at the Alpha stage.
Here are the key features we want to implement before releasing a Beta version:
- [x] Loader
- [x] HTML parser and DOM tree
- [x] Javascript support
- [x] Basic DOM APIs
- [x] Ajax
- [x] XHR API
- [ ] Fetch API
- [x] DOM dump
- [ ] Basic CDP server
We will not provide binary versions until we reach at least the Beta stage.
NOTE: There are hundreds of Web APIs. Developing a browser, even just for headless mode, is a huge task. It's more about coverage than a _working/not working_ binary situation.
You can also follow the progress of our Javascript support in our dedicated [zig-js-runtime](https://github.com/lightpanda-io/zig-js-runtime#development) project.
## Build from sources
We do not provide yet binary versions of Lightpanda, you have to compile it from source.
### Prerequisites
Lightpanda is written with [Zig](https://ziglang.org/) `0.13.0`. You have to
install it with the right version in order to build the project.
Lightpanda also depends on
[zig-js-runtime](https://github.com/lightpanda-io/zig-js-runtime/) (with v8),
[Netsurf libs](https://www.netsurf-browser.org/) and
[Mimalloc](https://microsoft.github.io/mimalloc).
To be able to build the v8 engine for zig-js-runtime, you have to install some libs:
For Debian/Ubuntu based Linux:
```
sudo apt install xz-utils \
python3 ca-certificates git \
pkg-config libglib2.0-dev \
gperf libexpat1-dev \
cmake clang
```
For MacOS, you only need cmake:
```
brew install cmake
```
### Install and build dependencies
#### All in one build
You can run `make install` to install deps all in one (or `make install-dev` if you need the development versions).
Be aware that the build task is very long and cpu consuming, as you will build from sources all dependancies, including the v8 Javascript engine.
#### Step by step build dependancy
The project uses git submodules for dependencies.
To init or update the submodules in the `vendor/` directory:
```
make install-submodule
```
**Netsurf libs**
Netsurf libs are used for HTML parsing and DOM tree generation.
```
make install-netsurf
```
For dev env, use `make install-netsurf-dev`.
**Mimalloc**
Mimalloc is used as a C memory allocator.
```
make install-mimalloc
```
For dev env, use `make install-mimalloc-dev`.
Note: when Mimalloc is built in dev mode, you can dump memory stats with the
env var `MIMALLOC_SHOW_STATS=1`. See
[https://microsoft.github.io/mimalloc/environment.html](https://microsoft.github.io/mimalloc/environment.html).
**zig-js-runtime**
Our own Zig/Javascript runtime, which includes the v8 Javascript engine.
This build task is very long and cpu consuming, as you will build v8 from sources.
```
make install-zig-js-runtime
```
For dev env, use `make iinstall-zig-js-runtime-dev`.
## Test
### Unit Tests
You can test Lightpanda by running `make test`.
### Web Platform Tests
Lightpanda is tested against the standardized [Web Platform
Tests](https://web-platform-tests.org/).
The relevant tests cases are committed in a [dedicated repository](https://github.com/lightpanda-io/wpt) which is fetched by the `make install-submodule` command.
All the tests cases executed are located in the `tests/wpt` sub-directory.
For reference, you can easily execute a WPT test case with your browser via
[wpt.live](https://wpt.live).
#### Run WPT test suite
To run all the tests:
```
make wpt
```
Or one specific test:
```
make wpt Node-childNodes.html
```
#### Add a new WPT test case
We add new relevant tests cases files when we implemented changes in Lightpanda.
To add a new test, copy the file you want from the [WPT
repo](https://github.com/web-platform-tests/wpt) into the `tests/wpt` directory.
:warning: Please keep the original directory tree structure of `tests/wpt`.
## Contributing
Lightpanda accepts pull requests through GitHub.
You have to sign our [CLA](CLA.md) during the pull request process otherwise
we're not able to accept your contributions.