SAIL (Self-Assembling Interface Layer), a scripting language provided by Appian. It is the equivalent of JS and CSS. It allows creation of complex UIs which are also responsive. With SAIL, we have a single language for both the UI logic and its appearance. UI components can be built as reusable components and used in multiple UI interfaces.
Process Modeling enables creation of business process workflows. You can create complex business workflows in a visual manner, and it is also easy to debug/monitor.
Offline capabilities and responsive capabilities could be better. The mobility features of Appian platform are still evolving.
Native mobile capabilities or hybrid mobile app capabilities are very limited. Things like offline sync, offline storage, access to smartphone device features, etc. are not supported by the Appian platform yet.
Three to five years.
It is Java based, can be deployed in JBoss or WebSphere container.
I would rate it eight out of 10. It certainly is the best for enterprise application development.