cclib is a Python library for parsing and interpreting the results of computational chemistry packages. It currently parses output files from ADF, GAMESS (US), GAMESS-UK, Gaussian, Jaguar, and PC GAMESS. Among other data, cclib extracts coordinates, atomic orbital information, molecular orbital information, information on vibrational modes, and the results of a TD-DFT calculation. cclib also provides some calculation methods for interpreting some electronic properties of molecules using analyses such as Mulliken population analysis, overlap population analysis, and calculation of Mayer's bond orders.
xylib is a portable C++ library for reading files that contain x-y data from powder diffraction, spectroscopy, or other experimental methods. Supported formats include plain text (CSV or TSV), Crystallographic Information File for Powder Diffraction (pdCIF), Siemens/Bruker UXD, Siemens/Bruker RAW v1/2/3, Philips UDF, Philips RD (raw scan) V3, Rigaku DAT, Sietronics Sieray CPI, DBWS/DMPLOT data file, Canberra MCA, XFIT/Koalariet XDD, RIET7/LHPM/CSRIET/ILL_D1A5/PSI_DMC DAT, Vamas ISO14976, and Princeton Instruments WinSpec SPE.
MathGL is a library for making high-quality scientific graphics under Linux and Windows, fast data plotting and handling of large data arrays, working in window and console modes, and easily embedding into other programs. It has more than 40 general types of graphics for 1d, 2d, and 3d data arrays. It can export graphics to raster and vector (EPS or SVG) formats. It has an OpenGL interface and can be used from console programs. It has functions for data handling and MGL language scripting for simplification of data plotting. It has several types of transparency and smoothed lightning, vector fonts and TeX-like formula drawing, an arbitrary curvilinear coordinate system, and many other useful things.
JavaPlot is a library that can be used as a way to create gnuplot plots on the fly through pure Java commands. In contrast with other common gnuplot Java libraries, it uses Java structures to store the various plot parameters, including datasets. Moreover, it is flexible enough to give special parameters to gnuplot, even if the library does not yet support it. It uses Java's Exceptions to inform the user if something went wrong.
Freeverb3 is a signal processing library. It includes many types of audio processing effects and signal generators including a linear feedback shift register (LFSR) maximum length sequence (MLS) generator, multiple types of high quality mono+stereo reverb effects, a multi slot impulse response processor, multiband hardknee+softknee compressor and limiter, a stereo enhancer, a limiter, and many types of infinite impulse respose (IIR) and finite impulse response (FIR) filters. Also available is Freeverb3VST, a VST effects plugins package based on the Freeverb3 library.