Opus is neuter/neutral(?) - what is the word for neither feminine or masculine - so adjectives end in -um unless of course you are using one of the other endings like "towards progress" etc etc.

The plural of opus is opera, so maybe you can make a musical double-entendre, just for fun by calling it "works in Progress" instead. The works progress, the opera progresses??

Helen Rusty Latin-lover/ lover of rusty Latin / lover of rusty Latin lovers / lusty Latin rovers.......ad nauseum