I am not sure about Live JS, but I have used Anchor CMS / http://anchorcms.com / and I have been pretty happy with it, with a few exceptions. It is small and lightweight, can easily be self-hosted and has a nice selection of themes/ http://anchorthemes.com / and you can easily make your own design. It powers my own personal blog and visiting anchorshowcase.com will show you some more blogs powered by it.
The thing about it that I don't like that much are :
1. Really weak plugin ecosystem. If you want something specific, you will probably have to make it yourself, as the CMS doesn't even have a plugin support, you have to edit things in the code.
2. Written in PHP. I know Python, not PHP so making changes for me is especially hard so anything complex for me is a no no.
3. It has been in development for a bit and the development has slowed while they are trying to build the 1.0 version.
I use Concrete5. Its not really meant for blogs, but it doe have blog functionality as well. You can make some really beautiful sites with it with not a ton of effort.
FWIW my blog comes from a static compiler, which has comments which are received via HTTP-posts and folded into the next time the blog is built, but there's no real live-JS.
The thing about it that I don't like that much are : 1. Really weak plugin ecosystem. If you want something specific, you will probably have to make it yourself, as the CMS doesn't even have a plugin support, you have to edit things in the code. 2. Written in PHP. I know Python, not PHP so making changes for me is especially hard so anything complex for me is a no no. 3. It has been in development for a bit and the development has slowed while they are trying to build the 1.0 version.