Convert OPF to RB

The Open Packaging Format (OPF) is a critical component in the EPUB digital publishing standard, specifically designed for eBooks. OPF files serve as a manifest that organizes and structures the contents of an EPUB file, including metadata, the reading order, and resource files. This standard, introduced by the International Digital Publishing Forum (IDPF) in 2007, aimed to streamline the publication and distribution of eBooks, ensuring compatibility across various devices and reading software. The OPF's primary purpose is to enhance the accessibility and interoperability of digital content within the rapidly evolving landscape of electronic publishing.

The RB file extension stands for Rocket eBook File, used by the Rocket eBook device from NuvoMedia, introduced in 1998. It is a container format for eBooks, typically holding HTML content and metadata. Although it supports DRM, modern eBooks no longer use this feature. The format includes a unique file structure with specific byte sequences for versioning and content organization.