libosl, the object storage layer, is a library for storing small to medium-sized data in relational tables. It is easy to use, lightweight, fast and portable. libosl is suitable for applications that need only a small fraction of the features a full database management system provides. Libosl is simple: - For libosl, all data stored in the osl tables are blobs, libosl will never try to interpret the table contents. - There is no fancy query language but only a relatively simple C-API. - There's no support for network-access and libosl only uses a very rudimentary table locking mechanism. - There are no dependencies on external libraries. An augmented version of the red-black tree implementation of the linux kernel is in included in the libosl package. Libosl is fast: - It uses sha1 hashes for content-based addressing. - Red-black trees are used to make lookups fast. Libosl is portable: - It is known to compile and run on Linux, MacOS, FreeBSD, NetBSD and Solaris. - Content and metadata is stored in an endian-agnostic way. Libosl is open source: - Licensed under the GPL, version 2. Apart from the library itself, the package also contains simple examples and an fsck program, oslfsck, which can be used to recover from corrupted tables due to system crashes or bugs in the application or the library.