I use Buzz tools I find it very user friendly

I use Embrilliance Thumbnailer...all single designs are displayed as images on my documents page (that's where I keep them before categorizing into folders). Once in folders, pix will display as named,..open the folder and you have a page of images to choose from. Another good viewer us sew icons from s&s computing. You can try this one in a free trial download.

If you are also on Facebook, join NobbieNees embroidery group. They have a free set of files in their files section.
Meri

I have Buzz Tools. Its not free, but worth every penny I paid for it! You can get a free trial version (I think?). It shows you your designs, plus will convert to your format. I have used Buzz Tools for over 15 years. Love it! Flowers to everybody!

Not free, but not expensive, I absolutely could not do without SewIconz. Files show on your computer as tiny pictures, hovering over them will give you size, stitch count and color count. Support is the best going-there is a yahoo group to join, as the programs are continually changing to meet the needs of the users.
I still have other software, but for ease wandering around my folders, this is it. At least go read about it, there are free trials of the software offered.
Jo

When I first started someone else was asking this and it was suggested for 'My Editor" - it's free. I have that on two computers. The one at my desk is not in my sewing room and I can look at any of the files. I just click on file and then browse, on the left will be a list - the one I click on is embroidery download designs and then there is a list with plus or a minus sign on the left of each file - click on the plus and it shows all the files you have in there and then click on a file and all the designs you have in that folder are shown on the right. Really easy to do.
Sometimes I find this easier to look through designs when looking for something than using my program I have with may machine.
When I started, one of the ladies where I got my machine said to make myself folders - like animals and sub folders in it with a type of animal as you need them, like dogs, cats, horses, whales, deet, etc. And do the same with other things. I don't usually have trouble finding things thanks to her.
Hope this helps! Good luck!

Here you go. this is free. It was originally from Tashambra Embroidery, but secrets of embroidery have it now for free...click on link, then click on 'this link' hope that helps you out...

Embroidery Library has a tutorial on setting up your computer.
Also my teacher told me to set mine up twice. One folder with Categories and ne folder with Companies.
So I have saved all my designs twice on my PC. If I want to find a flower, then I go to the Categories and look up 'Garden and Flowers'.
If I want to find a design from a particular company then I go to Companies and look up the company's name.
It is a lot of mucking around when you start out, but it works for me.
Good luck.

Missed the 2nd part of the question:
These are the 3 I have
Wilcom
Amazing Designs
Bernina have a freebie too
Google 'free software for machine embroidery' and you will find heaps.