mapping software

Hi all, I’m somewhat new to the weather enthusiast scene. What would be the best fully free radar software (preferably open source) out there for Windows? Is that kind of software even a thing?

Hi, I've looked for a post on S.T. for "Here We Go" offline mapping software and haven't found one. If there is one sorry for the repetition. This looks interesting (especially since it's free). Download maps for offline use and GPS tracking. Has anyone used this? Comments? Thanks, Jon