"My Application Server" allows you to run your own backend application server (a daemon process) on the web hosting hardware.
E.g. (just on the Java side) you can run:
- Apache Tomcat
- Jetty
- GlassFish
- JBoss
and more.
Node.js (JavaScript) and Phusion Passenger (Python, Ruby and more) are also supported by this control panel via different extensions, but you can run them via MyAppServer too.
Strictly speaking - MyAppServer allows you to run any long running program that is supported on the server hardware and the running Linux kernel. Yes, this means that you can run a program written in any language, either compiled (e.g. C/C++) or interpreted (e.g. PHP, Perl, Python) with or without a virtual machine (e.g. JVM).