APBS is a software package for the numerical solution of the Poisson-Boltzmann equation (PBE), one of the most popular continuum models for describing electrostatic interactions between molecular solutes in salty, aqueous media. Continuum electrostatics plays an important role in several areas of biomolecular simulation, including simulation of diffusional processes to determine ligand-protein and protein-protein binding kinetics, implicit solvent molecular dynamics of biomolecules, solvation and binding energy calculations to determine ligand-protein and protein-protein equilibrium binding constants and aid in rational drug design, and biomolecular titration studies.
PDB2PQR is a Python software package that automates many of the common tasks of preparing structures for continuum electrostatics calculations, providing a platform-independent utility for converting protein files in PDB format to PQR format. These tasks include adding a limited number of missing heavy atoms to biomolecular structures, determining side-chain pKas, placing missing hydrogens, optimizing the protein for favorable hydrogen bonding, assigning charge and radius parameters from a variety of force fields.
AGM Build is a molecular builder and conformational editor. It can be used for interactive model preparation for molecular dynamics simulations, including association of atom types and partial charges. It features geometry editing, lattice building, building of chain molecules (e.g. proteins), chains with predetermined conformations, and charges and atom types according to selected Force Field.
The Structural Proteomics Application Development Environment (SPADE) provides a community suite for developing and sharing protein structure and sequence tools. It includes a custom molecular viewer, sequence alignment editor, many reusable tools, and a chemical probing suite to support experimental verification of predicted structural models.
The massXpert software package is a mass spectrometry environment for linear (bio-)polymers. It inherits all the innovations of GNU polyxmass. It allows the detailed definition of new polymer chemistries in the XpertDef module. These chemistry definitions are then used in the desktop calculator-like mass calculator (XpertCalc) and in the sophisticated polymer sequence editor and (bio-)chemical/mass spectrometric simulations module (XpertEdit). Available simulations include polymer and monomer chemical modifications, polymer sequence cleavage, gas-phase fragmentation, m/z ratio calculations, and more.
VMD (Visual Molecular Dynamics) is designed for the visualization and analysis of biological systems such as proteins, nucleic acids, lipid bilayer assemblies, etc. It may be used to view more general molecules, as VMD can read standard Protein Data Bank (PDB) files and display the contained structure. VMD provides a wide variety of methods for rendering and coloring a molecule: simple points and lines, CPK spheres and cylinders, licorice bonds, backbone tubes and ribbons, cartoon drawings, and others. VMD can be used to animate and analyze the trajectory of a molecular dynamics (MD) simulation. In particular, VMD can act as a graphical front end for an external MD program by displaying and animating a molecule undergoing simulation on a remote computer. VMD uses OpenGL and OpenGL Programmable Shading Language for high performance rendering of large structures.
E-Cell System is an object-oriented software suite for modelling, simulation, and analysis of large scale complex systems such as biological cells. It allows many components, driven by multiple algorithms with different timescales, to coexist. The core library is written in C++ with a Python binding, and frontend software uses Python.
The Chemistry Development Kit (CDK) is a library of Java classes for chemo-, bioinformatics, computational chemistry, and chemometrics. It provides important algorithms like substructure search, SMILES, Gasteiger charges, QSAR descriptor calculation, 3D structure generation, 2D layout and rendering, many IO formats, atom typing, and more.