1)   PowerGREP 3.5.0
Quickly search through large numbers of files on your PC or network using powerful text patterns to find exactly the information you want. Search and replace with plain text or regular expressions to maintain web sites, source code, reports, ...
grep, egrep, regular expressions, perl, regex, regular expression, regexes, search and replace, search, replace,

 2)   RegexBuddy 3.1.1
Perfect companion for working with regular expressions. Easily create and clearly understand regex patterns. Test any regex on sample strings and files. Use the regex with automatic source code snippets. Collect regex libraries for future use.
regex, regexp, regular expression, regular expressions, grep, search, pattern, replace, split, egrep,

 3)   EasyPattern Helper 2.8
Design perl patterns using point and click! Just highlight the variable text and the text to capture, and EPHelper does the rest! EasyPatterns are a cool new way to describe text patterns. They're English-like, powerful and easy to understand.
ezpattern, ezpatterns, easypatterns, easypattern, perl, grep, egrep, pattern, easy pattern, easy patterns,