This is a great piece of software. In the past I've used Express Scribe but found that its use of wav files cause a huge consumption of disk space. F5 uses .mp3 files and is very efficient. The transcription window has all the features you need. It is document based so you can have as many open windows as you want. The text of the transcription is saved as an rtf which can be opened with a word processor or re-opened in F5. The time stamp feature lets you efficiently move within the transcription easily. The keyboard commands are user-defined so that's convenient too. Although it is free, they do ask for a donation of 10 euros. I like this software so much that I actually donated twice. There aren't very many choices for transcription software for Mac, but that works out fine because this one has just what is needed.