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.
DocuSign [eSignature Web App] and DocuSign Transaction Rooms (DTR) are two separate applications. DTR is a Real Estate specific document management tool. It allows Brokers and Agents to Manager their transactions effectively through a connected experience. You can create and close transactions electronically in the cloud-based software. Within a Transaction Room, you create a connected experience by inviting all the necessary participants.