XView binary compatibility (taking any OpenWindows V2 application dynamically linked against OpenWindows V2 XView, pointing the application towards V3 XView libraries and expecting the application to run) is supported with two possible exceptions:
XView 2.0 contained an interim API to shield clients from changes in the underlying Drag-and-Drop protocol. Applications that used this interface to "receive drops" will be fine when run against OpenWindows V3 libraries. However, if an application attempted to handle the protocol exchange itself, it will need source level changes.
XView applications that use the XVPS are not supported in Solaris 2.x.
An OLIT application written to the OpenWindows V2 libraries will run without problems using the OpenWindows V3.3 libraries with one exception: Drag-and-Drop support. An OpenWindows V2 application that attempts to use the Drag-and-Drop facilities in the OpenWindows V3.3 libraries will not succeed: the drop will fail. Cut and paste will work without problems. Due to the changes in the underlying Drag-and-Drop protocol, an application needs source level changes to continue supporting Drag-and-Drop.
Applications written using any version of TNT or Lite toolkits are not supported in Solaris 2.x.
The DeskSet applications available with OpenWindows V2 and OpenWindows V3 are still available with OpenWindows V3.3. Running OpenWindows V2 or V3 Deskset applications on Solaris 2.x is not necessary or supported.