I was just dealing with a large medical client yesterday whose big name time tracking app requires v6 (v6!) of Java, while our own medical app requires v8
Pro business tip: Survey your potential customers before starting a project to gauge what the requirements are.
For example:
When was your infrastructure installed or last received a major system-wide upgrade?
A. earlier than 2006
B. 2006-2011
C. 2011-2014
D. later than 2014
(A=Java 5, B=Java 6, C=Java 7, D=Java 8) These are all rough guesses, not absolutes, but if you ask enough other questions and survey enough potential customers it makes a real difference when planning. It's good to know in advance if supporting some obscure requirement is worthwhile, sometimes the extra business you would get is not enough to justify the development costs. (it would have to be a very tiny amount of business or a very high costs for that to really happen, but a programmer can dream can't he?)
A few well pointed questions can help you get a sense of what software requirements are customer is going to have.
If you aren't coding against requirements, what do you code against?