What are the good editor de shell script para Mac?

Dear Experts
I am using MAC OS X 10.8 on my laptop. I am looking for a full version of the shell script editor in Mac which also supports editing of large script files, find and replace option in files and much more.
Please suggest me which is easy-to-use freeware for editing shell scripts.
I want the best editor de shell script para mac.
Thanks.
