Osi (Open Solver Interface) provides an abstract C++ base class to a generic linear programming (LP) solver, along with derived classes for specific solvers. Many applications may be able to use the Osi to insulate themselves from a specific LP solver.

Osi is part of the larger COIN-OR initiative (Computational Infrastructure for Operations Research).

This package contains the abstract Osi base library; implementations for different solvers are provided separately. The OsiClp interface is provided by the clp source package.