I'm building (and have been for the last few years) an open source high-performance Wordpress alternative on Elixir. It aims to achieve 1:1 feature parity. One thing that Wordpress has built up over the years that will take a little long for me is the plugins eco-system. But, other than that, I think everything else should be on par. IF you're an enterprise, you should easily see over 30-40% in server costs just by switching from Wordpress. This has been tested and proven with one of our enterprise clients who just recorded 500 million requests on a fork of the CMS.
But, I'm determined to see its completion even if there is just one user. I didn't take the Wordpress fiasco and how they handled it, lightly at all and it only fueled my motivation even more. ETA is by end of this year right on time for Christmas.
If you'd like to read more, here's an article about my CMS: https://medium.com/creativefoundry/what-i-learned-as-an-arti...
If you'd like to get Beta access, my email is listed in my profile.
I don't know if Wordpress has any kind of customizability or scripting, but it's now possible to add Lua scripting, natively, to an Elixir application. If that's handy it's something to consider.
https://news.ycombinator.com/item?id=43972485