#1 myBalsamiq
myBalsamiq website | myBalsamiq demo
Cost: Starter Plan – $24/month (10 Active Projects, Unlimited Mockups, Unlimited Users, 50% off Desktop app, SSL Security)
Platform: web, desktop
Export options: png, pdf
Online preview
Real time collaboration and live preview
Versioning
Comments
Community
A lot of useful components
Sketchy style
Possibilities: 
Design: 
#2 UXPin
Cost: Freelancer’s Friend – $27/month (10 projects, 2 users, Paper prototypes recognition, 10% discount on UXPin Kits, Unlimited storage)
Platform: web
Export options: html
Online preview
Real time collaboration and live preview
Versioning
Comments are separated from mockups
Master elements
Nice interface
Possibilities:
Design:
#3 justproto
justproto website | justproto example
Cost: Plus – PLN 149 / month (12 collaborators, 25 projects, 5 GB server space)
Platform: web
Export options: html
Online preview
Real time collaboration and live preview
Comments
Master elements
Possibilities:
Design:
#4 Axure
Cost: $589 per license
Platform: desktop
Export options: png, html
Online preview
Versioning
Master elements
Interactive
Word specification generator
Possibilities:
Design:
Comparison:
| Name | myBalsamiq | UXPin | justproto | Axure |
| Cost | $24/month | $27/month | PLN 149 / month | $589 per license |
| Platform | web and desktop | web | web | desktop |
| Export options | png, pdf | html | html | png, html |
| Online preview | yes | yes | yes | yes |
| Real time collaboration and live preview |
yes | yes | yes | no |
| Versioning | yes | yes | no | yes |
| Comments | yes | yes | yes | no |
| Community | yes | no | no | no |
| Master elements | no | yes | yes | yes |
| Possibilities | 3 | 2 | 2 | 3+ |
| Design | 2 | 3 | 2 | 3 |