Old versions of browsers: support or not support?

Question

Do you think it is relevant to optimize the code to support older versions of browsers? i.e. refuse from new comfortable methods, etc.

Answer 1

It really depends on your target user and it's common to have an outdated browser from government/big corporate PCs. (IE8 anyone?)

If they are ignorant to the security issues caused by old browsers and refuse to change, then you got no choice but to support them as your client. 😉