It's a simple text file.. you can open it with any text editor (e.g. notepad on windows.. or vim on linux).

However, I'd recommend that you use the axlsql toolkit just as an example of how you do sql via axl.. and use it as a starting point for your own application. I built my own GUI based sql tool which works a bit like Microsoft's SQL tools - in the end I think that's what every programmer looks for and the axlsqltoolkit is way too clumsy to be used efficiently.