rtai-source software package provides Real Time Application Interface (module source), you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install rtai-source
rtai-source is installed in your system.
Make ensure the rtai-source package were installed using the commands given below,
$ sudo dpkg-query -l | grep rtai-source *
You will get with rtai-source package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Development |
| Package | rtai-source |
| Version | 3.9.1-4 |
| Description | Real Time Application Interface (module source) |
| Sub Section | devel |