Though the Sabayon 4 DVD release comes with SCIM , it's not possible read Malayalam or write using swanalekha by the usual methods. Let's see how to do it.
Type in terminal:
#cp AnjaliOldLipi.ttf /user/share/fonts/
Now you can read Malayalam :), To type using swanalekha, do the following :
#tar -xvf install-swanalekha.tar.gz
It's done, Right click the text box, select "SCIM input method" and start typing !!
Unfortunately this is not working in firefox. Please inform me if there is any mistake or bug. Thanks to SMC :)