...It was primarily developed to be used in combination with the Launchbox FE, since it didn't have a whole lot of support for importing MAME/Arcade games back in the day, but overtime it evolved into a fully independent list generator that can now be used to create game lists to a variety of FEs. When it comes to Launchbox, it's designed to use local metadata and artwork, so if you already have roms/artwork/support files locally, then you will be able to import your collection into Launchbox, fully configured in just a few seconds, completely filtered and ready to be played, thanks to an extensive number of filters available...
Lightspeed is geared towards LaunchBox but can create a customized MAME.xml for use with other Frontends. It has over a hundreds filters allowing you to create a very personalized list of games.
As a side note, you can apply all the filters and simply use Lightspeed itself as a frontend. Simply right click on a game in the list and select "play game".