  Through the development of a parallel code called TMSWIFT, an extensive
light-front quantization study of the nonperturbative spectrum of the bound
state $(\mu^+\mu^-)$, true muonium, has been performed. Using Pad\'{e}
approximants, it has been possible to extract continuum and infinite-cutoff
limits for the singlet and triplet states for a range of values of the coupling
constant $\alpha$. This data set allows for an investigation of the $\alpha$
dependence of the light-front spectra, the results of which are compared to
standard calculations. Decay constants have also been obtained. Improved
calculations have been undertaken for the energy shifts due to the presence of
a second, lighter flavor ($e$). Finally, initial results for three-flavor ($e$,
$\mu$, $\tau$) calculations are presented.
