Question: how install kdiff3 on ubuntu?
Answer: Download the Kdiff3 tar file from the sourceforge repos, then extract the tar file. ... 
Extract the tar.gz file using tar command. ... 
Make sure you have QT4 installed . ... 
After extracting go into the “src-QT4″ directory and compile. ... 
Now you should be able to launch the program by typing kdiff3 in the console.