FGCluster runs spectral clustering onto Healpix maps for parametric foreground removal, using a map encoding the feature to cluster as inputs. Pixel similarity is given by the geometrical affinity of each pixel in the sphere. FGCluster can also take an uncertainty map as an input, in which case the adjacency is modified in such a way that the pixel similarity accounts also for the statistical significance given by the pixel values in a map and the uncertainties.

Astromodels defines models for likelihood or Bayesian analysis of astrophysical data. Though designed for analysis in the spectral domain, it can also be used as a toolbox containing functions of any variable. Astromodels is not a modeling package; it provides the tools to build a model as complex as one needs. A separate package such as 3ML (ascl:2506.018) is needed to fit the model to the data.

The Multi-Mission Maximum Likelihood framework (3ML) provides a common high-level interface and model definition for coherent and intuitive modeling of sources using all the available data, no matter their origin. Astrophysical sources are observed by different instruments at different wavelengths with an unprecedented quality, and each instrument and data type has its own ad-hoc software and handling procedure. 3ML's architecture is based on plug-ins; the package uses the official software of each instrument under the hood, thus guaranteeing that 3ML is always using the best possible methodology to deal with the data of each instrument. Though Maximum Likelihood is in the name for historical reasons, 3ML is an interface to several Bayesian inference algorithms such as MCMC and nested sampling as well as likelihood optimization algorithms.