Which one is better on Linux? Valgrind or Purify What is your opinion of using them?
I have used both and valgrind is the clear winner for me. Not only is it free and open source, but it is much easier to use because it requires no recompile or relink. I've also found that purify is much more likely to change the behavior of your program, even causing it to produce incorrect results when the program is correct.
The valgrind team conducted a survey where valgrind was compared to other tools, including Purify, and posted the results on their site. According to this it looks like the big plus for purify is the GUI. Valgrind does not come with a GUI but there are GUI front ends available. I prefer the text output myself.