.BLOCKMAP File

File extension blockmap is best known for one of te XML files that can be found in Windows installer app packages.

According to Microsoft, the package block map file is an XML document that contains a list of the app’s files along with indexes and cryptographic hashes for each block of data that is stored in the package.

How to open:

Can be edited using any text editor (it's XML file), but meant to be used inside app packages.

How to convert:

It is unlikely any useful conversion exists.