They may have third-party code they aren't allowed to release.

Edge isn't very portable outside of Windows, it's just the cleaned up and refactored IE Trident engine. The same one we've technically been using for two decades.

> it's just the cleaned up and refactored IE Trident engine. The same one we've technically been using for two decades.

Then why does IE still exist alongside Edge?

because IE is still being used in some places.

In some very wealthy places that don't want to change.

I heard NASA uses IE

Open source contributions could ease development cost a bit, but cost isn't the main concern. The concern is compatibility, security, and performance which almost no amount of resources could get Edge up to par.

However, a radically new browser engine like Mozilla's Servo has a chance at performing so well, and reducing security vulnerabilities, that it seems like the only viable hail mary left for surpassing Chromium.

Also, these options aren't mutually exclusive. They could've decided to open source Edge but also switch to Chromium.

It would be interesting to have the code for Edge.

Just read his news, horrible. Only Apple and Mozilla left to try to keep a counterbalance. If this trend keeps up, soon the web will require a Blink/Chromium OS to run. Google already has way too much influence on the web.

EDIT: Considering the relatively slow speed of Safari development, I would not be surprised if they also would switch their base to Blink.

While it’s certainly not impossible, I would be pretty shocked if Apple dropped WebKit in favor of Blink. The entire reason Blink was forked in the first place was Apple and Google’s differing ideas on which direction to take the project.

Where Google favors getting new features in at a breakneck pace and sees the browser as an OS-like platform where the developer rules supreme, Apple favors power efficiency and sees the browser as a content portal where developers can’t be trusted to work in favor of users. These two models are fundamentally incompatible.

And then magically other people will start doing maintenance for free?

Perhaps, perhaps not, nevertheless why not opensource? I would just remove the word "instead" from the question.

They’d still need to invest a lot into it, to make it to the level that Blink is at, and they would still be fighting the Chromium/Blink network effects that brought us to the point we are at today. It would just be another (technically) inferior browser engine.

Surely it's just far too OS dependent?