There are a few others but all with their own caveats -
https://www.ekioh.com/flow-browser/ is fully independent and can run Gmail, but it's commercial / non-FOSS. It's funded by contracts in the set-top-box industry.
https://sciter.com/ is non-FOSS with a free edition but you shouldn't run untrusted javascript on it
And there are some lightly-maintained forks of the leaked Presto 12.x engine from before Opera became a Chromium derivative, but of course it's copyright infringement.
I would love if Opera open sourced Presto. It's unfortunate that the lack of resources that pushed them to Chromium probably translate to a lack of resources needed to open source Presto properly, so I doubt we'll ever see it. : \
https://www.ekioh.com/flow-browser/ is fully independent and can run Gmail, but it's commercial / non-FOSS. It's funded by contracts in the set-top-box industry.
https://sciter.com/ is non-FOSS with a free edition but you shouldn't run untrusted javascript on it
And there are some lightly-maintained forks of the leaked Presto 12.x engine from before Opera became a Chromium derivative, but of course it's copyright infringement.