flexml software package provides Fast validating XML processors and applications generator, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install flexml
flexml is installed in your system.
Make ensure the flexml package were installed using the commands given below,
$ sudo dpkg-query -l | grep flexml *
You will get with flexml package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Development |
| Package | flexml |
| Version | 1.9.6-5 |
| Description | Fast validating XML processors and applications generator |
| Sub Section | devel |