From Match Software
Manage all your .ttf, .otf, .dfont and .ttc files without smothering Font Book. Support of Classic Mac OS 7.5-9.xx Font Suitcases.
Drag entire fonts folders into Fonts Manager, and see them displayed without having to install them first. Try them out at a click of the mouse, and see how they look with your own typing at sizes between 8 and 500.
Add and activate entire folders.
Activate and deactivate fonts in a single click on a check box. Activate and deactivate entire folders. Very convenient for graphic projects, so you can keep all the fonts needed neatly tucked into a single folder which can then be passed to the Typesetter or Printer all at once.
This app installs and manages elegantly the 1700+ Google Fonts, usually web oriented. Display them and activate or deactivate each in a click, without bloating Font Book content. Once activated, they will show in all standard Mac OS X applications : word processor, desktop publishing, graphic applications, presentations, etc.
Fonts Manager lets you manage all the fonts you want without having to install them in the system or copy them into Font Book. It displays all of them in their own style, and checking a box will make them available to all standard Mac applications.
The Google Fonts
OS X 10.7 minimum
30 days full functionality