I am wondering if there is anything similar to ink over apps for linux. i.e. , a program that allows me to draw over any other program given Xs architecture, it should be possible, but I looked for it and could not find it.
EDIT: I have two good suggestions by Roman Raguet: one in his answer, and one in the comments.
I'd like more suggestions, and, if possible, one that does not require a composite window manager
Best Answer
EDIT:
Option 1 (compiz composite manager)
As far as I read about the ink over apps application... you can try with the "Annotate" plugin in compiz.
1) Intall the compizconfig-settings-manager, compiz-plugins and the compiz-plugins-extra packages running code below.
2) Open the compizconfig-settings-manager application.
3) Go to the "Extras" category and enable the "Annotate" plugin.
4) Click in the plugin to view and set the configuration.
5) configure the plugin according to your needs.. here you have an example.
You can launch whatever application, draw in it and use the shorcuts for the gnome-screenshot app like Alt + Print to take the screenshot of the windows you drew.
Option 2 (with any composite manager eg: xfce, compiz, xcompmgr etc)
Another software to draw over the desktop is Ardesia.
1) To install Ardesia, open a Terminal and type:
sudo apt-get install ardesia
2) To open the app eg: Xubuntu.
Go to Menu > Accessories > Ardesia Desktop Sketchpad
3) You can draw over and app or your desktop and you can take screenshots with the Ardesia toolbar.
Option 2.5
If you have a slow computer, you might want to try option 2 using lxde and xcompmgr (a lightweight composite manager)
To run lxde and xcompmgr,
1) Install both programs
2) follow the instructions at How to start applications such as xcompmgr at start up? to get xcompmgr to start in lxde
This option works rather well, even on slow computers.
Option 3 (without composite manager)
Another application to draw but without a composite manager is Pylote.
To run Pylote you need first python (greater than or equal to 2.6) installed by default in Ubuntu, and python-qt4.
1) Open a Terminal window and type:
sudo apt-get install python-qt4
2) Download the pylote.tar.gz file. (Pylote install GNU / Linux)
3) uncompress the tar.gz file
tar xvzf /path/to/pylote.tar.gz
4) Enter in the pylote folder and make sure the file pylote.pyw has execute perms.
cd /path/to/folder/pylote
chmod 755 pylote.pyw
5) Run the pylote app with double click in the pylote.pyw file
6) Take an screenshot after drawing over an app or your desktop. eg: scrot
sudo apt-get install scrot
Then you can hit Alt+F2 and type
scrot -s /path/to/your/screenshot.jpg
with the -s option you can select the area to take the screenshot and save at .jpg.
Hope this will helpful.