lxtask software package provides LXDE task manager, 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 lxtask
lxtask is installed in your system.
Make ensure the lxtask package were installed using the commands given below,
$ sudo dpkg-query -l | grep lxtask *
You will get with lxtask package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | X Window System software |
| Package | lxtask |
| Version | 0.1.4-3.1ubuntu1 |
| Description | LXDE task manager |
| Sub Section | x11 |