Gherkin syntax files are just plain text so any editor such as notepad can be used. However, one of the more important things we are using this for is to provide tables of sample data. Without good formatting options the files become hard to read.
There are some good tools (see: How to get Gherkin syntax highlighting for .feature files in Visual Studio?) for visual studio such as specflow.org or https://github.com/henritersteeg/cuke4vs. Another option for developers using eclipse is discussed at Cucumber IDE for feature writing with autocomplete? However I don't want to require it be installed for our business analysts.
Here is a syntax highlighter files (http://productive.me/develop/cucumbergherkin-syntax-highlighting-for-notepad/) that can be imported into notepad++ but it does nothing for table formatting.
Are there any other options that I might have missed for allowing non-developers to efficiently edit .feature gherkin files?
Here is a non-developer tool. We had a similar requirement and I wanted to have a stab at creating a Chrome extension. It's free and there are no ads. Above all it is cross-platform and requires no technical knowledge to install and run. https://chrome.google.com/webstore/detail/tidy-gherkin/nobemmencanophcnicjhfhnjiimegjeo
I know this is an old post, but I came across it when I was looking for a solution and I didn't think the answers fully addressed the OP's request for a non-dev tool (presumably aimed at a non-technical person).
It's a first attempt, so be kind! Hope someone finds it useful.