The HFile format based on Java serialization. Optionally, compression and XML serialization are supported. Data can be written sequentially or using the key-value maps.
The PFile format based on the Protocol Buffers engine for multiplatform input output
The HBook format, which is a simplified XML format to write large data structures without XML tags
Arbitrary data structure can be written into object databases with file system as back-end. This allows writing large data collections to files which normally do not fit into the computer memory.
Several SQL database engines are included as external packages
AIDA (computing) file format (read only)
ROOT file format (read only)