osama@osama-laptop:~/Desktop/fontforge$ sudo apt-get install x-dev
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Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libuninameslist0
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  x11proto-core-dev
The following NEW packages will be installed:
  x-dev x11proto-core-dev
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 10.7kB/96.9kB of archives.
After unpacking 520kB of additional disk space will be used.
Do you want to continue [Y/n]? y
Get:1 http://archive.ubuntu.com feisty/main x-dev 7.0.10-1 [10.7kB]
Fetched 10.7kB in 1s (9505B/s)
Selecting previously deselected package x11proto-core-dev.
(Reading database ... 106967 files and directories currently installed.)
Unpacking x11proto-core-dev (from .../x11proto-core-dev_7.0.10-1_all.deb) ...
Selecting previously deselected package x-dev.
Unpacking x-dev (from .../x-dev_7.0.10-1_all.deb) ...
Setting up x11proto-core-dev (7.0.10-1) ...
Setting up x-dev (7.0.10-1) ...