PLTMG 10.0 is a package for solving elliptic partial differential equations in general regions of the plane. It is based on continuous piecewise polynomial triangular finite elements (linear, quadratic and cubic), and features adaptive local mesh refinement, multigraph iteration, and pseudo-arclength continuation options for parameter dependencies. It also provides options for solving several classes of optimal control and obstacle problems. The package includes an initial mesh generator and several graphics packages. Support for the Bank-Holst parallel adaptive meshing strategy is also provided. PLTMG is provided as Fortran (and a little C) source code, in both single and double precision versions. The code has interfaces to X-Windows, MPI, and Michael Holst's OpenGL image viewer SG. The X-Windows, MPI, and SG interfaces require libraries that are NOT provided as part of the PLTMG package. PLTMG is available from Netlib, Mgnet, and on the software section of this web site.