We are pleased to report that based on our testing to date, Fetch 5.7.3 is compatible with Mac OS X 10.9 (Mavericks), aside from one minor issue.
That one issue, reported by a user and confirmed in our testing, is that the path popup menu sometimes does not appear when the Path button is clicked. Clicking the Recent button appears to fix this problem, at least temporarily. Command-clicking the window title to display the path menu is not affected. We will continue to investigate this issue to determine the cause.