A plugin for gedit is avialable. Using that you can read the text that you opened/typed in gedit. Download this plugin and keep it in your [HOMEFOLDER]/.gnome2/gedit/tools folder. Note that you should enable the external tools plugin in gedit(You can do this by edit->Preferences->Plugins->External tools)
Now you can see a menu named Dhvani in Tools menu of gedit. It has a shortcut key F11. Select some text in gedit and press F11. It will read the text. If you dont select any text and press F11, it will read the entire text.
If you want to enable this plugin for all users of your system, keep the plugin file in /usr/share/gedit-2/plugins/tools folder.
The binary packages install this plugin when they are installed.
It is possible integrate Dhvani KDE desktop through its TTS system KTTS. Using this you can dhvani can read the text in kate,kedit,kwrite, Konqueror. You can even listen to the text in the webpages in Konqueror Dhvani can be itegrated to KTTS using its Command plugin feature. To do this go to control center-->Regional and Accessibility -->Text-to-speech -->Talker Tab. Add a new Synthesizer.
Select the syntesizer type as Command and Langauge as Other. You can select any language since Dhvani doesn't want langauge parameter and it detects the language automatically. Give the synthesizer command as
Move this synthesizer to top in the list of Synthesizers and Click apply. Done. Now take a UTF-8 text in any of the editors described above or take a webpage in any of the supported language. From the tools menu take Speak Text and listen.