Serval - an Experimental Web Browser Engine

Serval is an experimental web browser engine written in Rust. The author (@hayatoito) is using Serval as a playground when designing and implementing a new idea or concept into the Web Platform, before starting to implement it actually in Chromium Blink engine in C++.

I'd love to have a small rendering engine which has only essential parts so I can experiment something new, and get insights from there quickly. Rust would be better than C++ for this kind of prototyping.

Highlights

• Serval is not for end users.
• Serval is an experimental minimum rendering engine. I only implement what I need for my experiments in the rendering engine.
• Some people might consider Serval as a good project for educational purposes, however, that is not my goal.
• Serval is my personal project. Serval is not related to Chromium Blink engine. I commit nothing about Serval.

Features

• DOM (element and text)
• HTML (This is NOT HTML which you know. Serval HTML is implemented as an s-expression, as of now)
• CSS (simple selector)
• Layout (block layout)
• Paint (canvas and png)
• Layout (inline layout)
• Paint (output as json)
• WASM binding, interpreter, JIT
• Shadow DOM
• Copy-on-Write shadow trees
• WebTemplate
• Parallel style recalc and layout
• Networking, asynchronous I/O based scheduling
• Interactive UI (I think which is never implemented)

Examples

Given the following HTML (in an s-expression)

(div class=a
     (div class=b
          (div class=c
               (div class=d
                    (div class=e
                         (div class=f
                              (div class=g))))))))

and CSS,

* {
  display: block;
  padding: 12px;
}
.a {
  background: #ff0000;
}
.b {
  background: #ffa500;
}
.c {
  background: #ffff00;
}
.d {
  background: #008000;
}
.e {
  background: #0000ff;
}
.f {
  background: #4b0082;
}
.g {
  background: #800080;
}

Serval can output png as follows:

> serval paint ./example.html ./example.css ./example.png png

example.png:

Acknowledgments

Matt Brubeck: Let's build a browser engine