The best, top rated, fastest, open source (free) Windows grep tool with a GUI

This post quickly reviews and recommend the best Windows Grep tools with a Graphical User Interface (GUI).  

A little backgrounder, grep originated from unix and now has linux and windows equivalents. It's a  command-line utility for searching within files for lines that match a text search or regular expression. Command-lines are difficult for the novice user to master hence the the need for a Graphical User Interface (GUI). 


This is an current popular list of current  Windows Grep tools with a Graphical User Interface (GUI) with issues I found; 

1. PowerGREP (paid $159 USD), 
2. Windows Grep (dead), 
3. Bare Grep (not open source, last update 2006, free unlimited trial, licensed is $25 USD), 
4. AstroGrep (open source, C# code base but super slow, tested personally), 
5. dnGrep (open source, C# code base but slow complaints by users)

The winner grepwin, an active open source initiative, last release 2017-04-08.

grepwin  "A powerful and fast search tool using regular expressions"

No. 1 for the following reasons; 

1. Speed, this project is coded in C and is super speedy
2. Open source and free, freely to inspect for malware and spyware, none so far
3. Flexibility, you can combine search for file names and/or search for content separately!