FlexiSign Pro 10.5 is an older iteration. While it was legendary in its time, the software was designed for older operating systems (Windows XP, 7, and early 8).
The software utilizes several floating windows and toolbars to streamline the design process: Flexi Single Product Page - ThinkSAi.com
If you are looking for a way to use the software without a massive upfront cost, consider these official channels: Subscription Model : SAi moved to a Flexi Subscription
Native drivers for thousands of plotters, allowing for precise tracking and weed-line generation. The Reality of "Free" Downloads
: Features advanced algorithms for selecting and editing colors, including support for Pantone Plus libraries and the ability to create ICC profiles.