On a web browser (Chrome, Firebox, Safari) and go to tqlr1.atomiton.com. Click on the "Sign Up" link.
Enter your name, email address and password to sign up. You will receive an email from "Atomiton Notifications" with an activation link. Activate your account by clicking on the link, or copy and paste the URL into your browser. Remember to check your spam folder if you don't see the email. You will be asked to accept the SaaS terms the first time you log in.
Refer to the TQLStudio Section of the docs for more information on the features.
How you can import and try a sample project on the sandbox Atomiton provides.
Once you are in the TQLStudio, you will also be able to download and install the TQLEngine in your own environment.