SciMLBase.jl is the core interface definition of the SciML ecosystem. It is a low dependency library made to be depended on by the downstream libraries to supply the common interface and allow for interexchange of mathematical problems.

The breaking changes in v2.0 are:

• IntegralProblem has moved to an interface with IntegralFunction and BatchedIntegralFunction which requires specifying prototypes for the values to be modified instead of nout and batch. SciML#497
• ODEProblem was made temporarily into a mutable struct to allow for EnzymeRules support. Using the mutation throws a warning that this is only experimental and should not be relied on. SciML#501
• BVProblem now has a new interface for TwoPointBVProblem which splits the bc terms for the two sides, forcing a true two-point BVProblem to allow for further specializations and to allow for wrapping Fortran solvers in the interface. SciML#477
• SDEProblem constructor was changed to remove an anti-pattern which required passing the diffusion function g twice, i.e. SDEProblem(SDEFunction(f,g),g, ...). Now this is simply SDEProblem(SDEFunction(f,g),...). SciML#489