Can I still use Paratext 7 after installing version 8?

Yes, Paratext 7 may continue to be used after installing version 8. However, the data will not be shared between versions 7 and 8; Paratext 8 can not collaborate with Paratext 7 and vice versa.  Users must migrate their data from 7 to 8 using the migrate feature in Paratext 8.