Q: Suggestions for alternate software to Aperture?

You can still use Aperture (at least now). If you previously purchased Aperture, it should be in your App Store Purchases list. If you don’t see it. it may be under Hidden Purchases. You can try downloading it from there.

If you haven’t erased your hard drive when upgrading to OS X 10.10.3, Aperture may be in your Applications folder.

The first or second system update removed both iPhoto and Aperture programs and ten "introduced" Photos. Photos is simpler and more iOS-like than iPhoto, and beyond the ability to create albums, but it's entirely unable to create the more complicated file management or editing that abilities that Aperture had.

Sally, the MacOS X 10.10.3 update did not remove Aperture or iPhoto. It just added Photos. But both Aperture and iPhoto should still be installed on your Mac and ready to use, if you did not uninstall them yourself.

Just drag Aperture and iPhoto from the Applications folder back to your Dock to make them accessible.

You may need to update both Aperture and iPhoto however, if you did not already update them to Aperture 3.6 or iPhoto 9.6.1.

If you did not yet update to Yosemite compatible versions, see these user tips:

Get iPhoto 9.6.1 if you didn't update before OS... | Apple Support Communities

Updating to Aperture 3.6 After the Release of Photos

I cannot say anything about Lightroom, because I have not much experience with it. I simply do not like the look and feel of the user interface.  From what I can tell, the User interface in Capture One is nmuch closer to Aperture.

But right now I am still mainly working in Aperture and using Photos to sync a selection of photos to al my devices.

Give  Pixelmator a try. Easy, user friendly. Create, edit, etc. 

If you are looking for something similar to Aperture, check out Capture One. There's a growing list of ex-Aperture users who seem to be moving in that direction. The forum at Phase One (the company that produces Capture One) may provide additional advice.

it installed Photos but the app icons for both iPhoto and Aperture were

The icons were removed from the Dock, but the applications are still in your Applications folder.

Hi, I had the same problem - I found CaptureOne Pro 8 as a replacement. After an initially steep learning curve it is now intuitive and imports Aperture catalogs very well. Image adjustments are better, IMHO,  than those offered by Aperture. Raw handling is excellent. Worth a try. Good luck!

Give  Pixelmator a try. Easy, user friendly. Create, edit, etc.

Actually, no.

Aperture is primarily a photo management software, whereas Pixelmator is primarily a photo editing software.

Photo Management: Aperture, iPhoto, Photos, Lightroom, Capture One, etc.

Photo Editing: Pixelmator, Photoshop, Photoshop Elements, Acorn, Gimp, etc.

Do you still feel this way Lanny? Are you happy with Capture One? How well does it actually manage a large photo library? Will the transition from Aperture to Capture One (or Lightroom for that matter) retain all the meta data, places, faces, titles, etc?

I have to assume that you want to repond to, "bcor."

You are right....it should have been directed to "bcor". Have you tried Lightroom and/or CaptureOne for managing your photo library?

Are you still using CaptureOne? With another year with it I am wondering if you are still happy with it? I asked Lanny this but should have asked you? Does CaptureOne retain all the iPhoto/Aperture metadata (places, faces, titles, etc)?

I use Lightroom. I have the $9.99 subscription for Lightroom and Photoshop. Lightroom takes a little getting used to, but it offers better features than Aperture.

I tried a demo of CaptureOne. It was nice, and a little more like Aperture in its operation, but for me, I couldn't justify the price. Especially because I'll always want Photoshop and paying for Photoshop and CaptureOne is just too expensive.

I also don't use Lightroom's default managed file sytem, by dates. I use a system organized by events:

Thanks for the input.