It is a given that accounting firms and corporates are not specialist tax software designers/builders, which is why spreadsheets are so common.
One of the most interesting learnings I have had recently has been that some vendors are already providing PTA software.
In my role, things regularly come out of the blue; earlier this week for instance, a call from a tax lawyer / barrister.
Computers, mobile phones, iPads, the auto-mobile, the Internet, the list goes on and on.