This paper presents PackUp (http://sat.inesc-id.pt/~mikolas/sw/packup). (PACKage UPgradability with Boolean formulations) a framework for solving the the software package upgradability problem. Earlier versions of the framework (cudf2msu, cudf2pbo) participated in the 3rd MISC-live, an international competition organized by the European project MANCOOSI. The framework encodes the problem as a weighted partial MaxSAT formula and invokes a dedicated solver to solve the formula. The framework supports two types of solvers: weighted partial MaxSAT solvers and optimization pseudo-Boolean (OPB) solvers. The paper discusses the design of the framework and the specifics of the problem encoding.