A library of nonlinear solution schemes including load, displacement, arc-length, work, generalized displacement, and orthogonal residual control are cast into a unified framework for solving nonlinear finite element systems. Each of these solution schemes differs in the use of a constraint equation for the incremental-iterative procedure. The governing finite element equations and constraint equation for each solution scheme are combined into a single matrix equation, which characterizes the unified approach. This theoretical model leads naturally to an effective object-oriented implementation and potential for integration into a finite element analysis code. Using this framework, the strengths and weaknesses of the various solution schemes are examined through several numerical examples.