Java is a programming language and computing platform first released by Sun Microsystems in 1995. There are lots of applications and websites that will not work unless you have Java installed, and more are created every day.
IIS is able to impersonate the IUSR_<computername> account because the user name and password for this account are known by IIS. Before returning a page to the client, IIS checks NTFS file and directory permissions to see if the IUSR_<computername> account is allowed access to the file.
IBR is an alternative student loan repayment plan available for FFELP and FDLP borrowers. Unlike other repayment plans, which may require a one-size-fits-all payment amount, IBR establishes a monthly payment that looks at your unique situation by considering your income, family size, and federal student loan debt.