Hello Uday, It is generally believed that Malayalam came from Tamil tho there was a lot of sanskrit influence later on.Old Kannada and Telugu have a lot in common with Tamil but it is difficult to trace which was the older language There are reasons to believe that Tamil was the oldest l;anguage..Burrow and Emenau have authored Dravidian Etymological Dictionary in which they have traced a large number of Dravidian languages.Both Kannada and Telugu in their present form have a lot of borrowing from Indo-Aryan,particularly sanskrit and prakrit. GR
My understandig is all the dravidian languages stemmed from Tamil with other influences
On the same note I am sure most of you will be aware of the fact that Sanskrit is the mother of all european languages and is computer compatible.
Tamil is one of the two spoken classical languages still the other being Greek(The rest are Persian,Sanskrit,and Latin)
Cannot honestly remember if Chinese and arabic were classed as Classical languages)
In the language tree it appears as Telugu,Kannada,Malayalam and Tulu stemming from tamil and each of them has a fair share of sanskrit and prathkrit mixture to it
I ll find if I can find the references and links I read about these in one of the Ancient languages website