The Oakwood Guidelines for the Oberon-2 Compiler Developers specifies a set of libraries that should be provided with all Oberon implementations. The current XDS release does not contain all these libraries yet. The following libraries are currently available:
| In | input from a standard stream |
| MathR | mathematical functions for REAL |
| MathL | mathematical functions for LONGREAL |
| MathC | mathematical functions for COMPLEX |
| MathLC | mathematical functions for LONGCOMPLEX |
| Out | output to a standard stream |
| O2Strings | simple manipulations for strings |
The Math library is renamed to MathR, because it coincides with the POSIX math library interface. The complex types and, hence, MathC and MathLC modules may be not available for other Oberon implementations.
The Strings library is renamed to O2Strings, since it is not compatible with the correspondent ISO library.