Photos

I have 20,000 + pictures on various formats, hard drives, CDs, DVDs, iPhoto etc.

What method or application should I use to put them

all into my new 5k iMac I'll be getting soon. I am not a big fan of iPhoto so looking for

another application that I can sort thru them and then store on an external hard drive once I've had the

chance to tag them for future reference. The photos that I "backed up" 10 years ago from iPhoto are not easy to open

as my newer MacBook doesn't recognize the iPhoto I used in the past?

Thanks for any suggestions.