@Gianluca
The main reason CoMaps and OsmAnd use different offline map formats is due to their distinct technical architectures and feature sets. OsmAnd’s .obf format is tightly integrated with its own rendering engine and supports advanced features like offline search, routing, and POI indexing directly within the app. This format is highly optimized for OsmAnd’s specific requirements, allowing for incremental map updates and in-app downloads.

CoMaps (like Organic Maps) uses the .map format, which is designed for fast rendering and efficient storage, but it typically requires the entire map file to be replaced for updates. This approach can make updates less flexible, as you’ve noticed, since you often need to update the whole map file or even the app itself to get new data.

The advantage of each format depends on priorities:

• OsmAnd’s .obf: More flexible updates, richer offline features, but potentially larger files and more complex indexing.
• CoMaps’ .map: Fast rendering, simpler structure, but less granular update options.

The use of different formats is mainly a result of these technical trade-offs and the independent development histories of both apps. For users, this unfortunately means map files aren’t interchangeable, and update mechanisms can differ significantly. Your point about in-app map updates is valid—OsmAnd’s approach is more convenient, while CoMaps’ method may be less flexible for frequent updates.