Today I read on Trolltech Labs Blogs a great post from Samuel Rødal about how to get translucent widgets on X11 with Qt's newest snapshot. Then I thought that if people find it cool to have such thing, why not say how to do the same in EFL?
EFL here is just Evas, Ecore and Edje. Evas does support rendering to semi-transparent buffers, including ARGB windows. Ecore and it's sub-libraries Ecore-X and Ecore-Evas know how to create ARGB windows since a long time, just use ecore_evas_alpha_set(ee, 1) if you have composite manager or ecore_evas_shaped_set(ee, 1) if you don't (it will be the best you can achieve on low end hardwares). Edje is just used to provide fancy button-like object without trouble, if you like Qt, then try QEdje.
My code is available at http://barbieri-playground.googlecode.com/svn/efl-tests/transp-bg/ and it requires a recent version of Ecore, not because of alpha/translucent support, but because I just added the helper ecore_evas_new(). If you have an older version, try to replace it with ecore_evas_software_x11_new(NULL, 0, 0, 0, 320, 240). Why I did used that function? First because I wanted to blog about it, second because it will make the same effect work elsewhere, like Windows and DirectFB ;-)