Its common discussion war between I.T people which technology is more progressive and customer oriented Java or .Net. I personally analyze the two and here I mention key differences between the two.

Key Differences Between Java and .Net

First clearing that Java is two things Java language and Java Platform. Similarly .Net is two things the .Net supported languages and .Net Platform. Now come to major difference which is root cause of differences between Java and .Net
The ideal of Java has always been a Single language shared by multiple Platforms. Whereas .Net is based on Multiple languages shared by single Platform. Now come to derived differences from this major difference.

1).Net has Multilanguage support. While java has based on java language only. According to Microsoft latest news .Net support around 40 languages including major market share COBOL, Vb.net, C#.net, Perl and many others.

2)Since java is multiplatform so it’s set of Framework Classes is limited to what is available on all platforms. While .Net has set of all the Classes available on Microsoft Platform.

3)According to Sun, Java is renowned as “Write once run anywhere”. While .net has no such scene. But my perception is, its not completely true to say “Write once run anywhere” but one aspect is that most of the applications written today focus on one platform only. Similarly to assure its multiple support much time needed to debug it on all platforms. So I would like to say Sun that it’s not “Write once run anywhere” but its “Write once and Debug everywhere.

4).Net due to disconnected data access through ADO.Net has hi level of performance against Java JDBC which requires multiple round trips to data base.

5)Java has support to open source platform while .Net has no direct support for Open source Platforms.