docbook-xml software package provides standard XML documentation system for software and systems, you can install in your Ubuntu 12.04 LTS (Precise Pangolin) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install docbook-xml
docbook-xml is installed in your system.
Make ensure the docbook-xml package were installed using the commands given below,
$ sudo dpkg-query -l | grep docbook-xml *
You will get with docbook-xml package name, version, architecture and description in a table
| Distro | Ubuntu 12 04 lts precise pangolin |
| Section | Text Processing |
| Package | docbook-xml |
| Version | 4.5-7ubuntu1 |
| Description | standard XML documentation system for software and systems |
| Sub Section | Text |