Part1: What is IPC 2581
The "new" PCB design data file format, IPC 2581, was released in 2004, together with the generic IPC DPMX standard for PCB and PCBA manufacturing. It is considered the best alternative to the Gerber file format and has gained popular uses worldwide.
All ECAD tools can output the IPC-2581 format, so it is a generic format like the Gerber format. Gerber (including 274X) is dumb, it is a graphic format without smart data. The IPC 2581 format is intelligent, its dataset includes stack -ups, netlist, traces, components, pins, vias. Using the IPC 2581 format, PCB manufacturers like PCBHERO don't need to spend much time on CAM before manufacturing your PCB design.
Some people use another smart PCB design format, ODB++. However, ODB++ is not a universal format, and only paid users of ODB-enabled software can read and use ODB++ files. Instead, not only do all ECAD tools support IPC-2581, but you can download a free IPC-2581 file viewer from the official IPC 2581 website.
However, the PCB industry can be very conservative at times. Gerber remains a common format for PCB designers and manufacturers.