This can be deposited in a variety of electronic formats.
Sometimes software is deposited in a format fully supported by a source control repository sometimes it is not.
For litigation purposes a version which is stored in a full source control repository format such as team foundation server is very useful as it should contain information about who made changes to code and when.
For information in relation to how to make a deposit click here.
This can be useful to ensure that you have a historical copy of what software was operating in your environment at what time and to ensure that the source code deposited matches the binaries currently in use.
For information in relation to verification click here
Supplier compilers and tool kits (other than those for which Customer has expressly approved in writing are not required).
This may seem excessive but as many escrow agreements are for long term projects there is no assurance that the Customer will be able to purchase the specific toolsets required to compile and use the source code.
This is particularly useful in a merger and acquisition scenario.
Depending on the volatility of that information it usually supplied on DVD/CD/Hard Disk/USB Key/Electronically.
More recently it is being supplied electronically for live trading environments.
Research Materials
This is particularly useful when a third party is required to state that materials were received on a particular date in relation to first to invent (eg USA) rather than first to file patent systems. (eg. Australia, Europe)
Passwords
Often a password to any sort of data is all that is required to be held in escrow.