are the salaries give after tax or before tax?

Before taxes.

Before tax always

before, since the amount of taxes taken out varies depending on your withholding status.

Always before taxes.

How would they know what deductions you have?

Salaries listed on salary surveys are before tax.

Before taxes. The same applies with other salary survey sites other than PayScale.com.

Before the local, state and federal government taxes the hell out of your salary. This depends on how many people( minor(s) or spouse) you declare as a dependent on your W-2. And where what part of the country you live in as well. For example the price of housing is higher in places like Washington D.C. or NYC. NY state has a 7% sales tax as well. Any salary is not possibly going to cover housing and living expenses after taxes are taken out.

the people offering jobs and quote the salary have NO way of knowing what income taxes you will be required to have deducted, thus they are quoting what the job pays, before taxes

Before

I think they're gross (pre-tax) salaries.

Before. Know that these sites are unreliable and should just be used to ballpark a salary, not as a hard-line negotiating number. I find they almost always overestimate pay, especially for early- and mid-career.

before

B-E-F-O-R-E