getstockquote is a Perl script which fetches stock and mutual fund data for one or more ticker symbols and returns an HTML table on STDOUT with each stock's data, including last trade price, day high, day low, change, last trade date/time, volume, open, close, bid, and ask. It can look up information from NYSE, NYSE Europe, Fidelity, T. Rowe Price, Vanguard, ASX (Australian Stock Exchange), and TIAA-CREF Annuities. It is completely configurable via command line arguments, and can be easily used by more than one page/script/etc. with no modification.
GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. The software aims to provide a unified and user friendly framework for editing structured documents with different types of content: text, mathematics, graphics, interactive content. TeXmacs can also be used as an interface to many external systems for computer algebra, numerical analysis, and statistics. New presentation styles can be written by the user and new features can be added to the editor using Scheme.
GnuCash allows you to track bank accounts, stocks, income, and expenses. As quick and intuitive to use as a checkbook register, it is based on professional accounting principles to ensure balanced books and accurate reports. It is backed by an active development community and is blossoming into a full-fledged accounting system.
Gnumeric is a powerful and easy to use spreadsheet using GNOME. Its goal is to provide a full featured spreadsheet and a smooth migration path for people and organizations currently using proprietary applications. It provides more sheet functions and greatly improved accuracy when compared to Microsoft's Excel. A plugin system lets you extend Gnumeric, adding functions, I/O formats, and real time data capabilities. The existing Python, Guile, and Perl plugins let you define complex functions. Gnumeric is capable of reading and writing MS Excel (XLS and Office Open XML), and reading Lotus, Applix, Quattro Pro, OpenCalc (ODF), XBase, DIF, SYLK, HTML, Psion, MPS, oleo, sc, misc. text formats, and its native XML. It can also generate Latex, HTML, and others.
GRPN is a RPN calculator for the X Window system built using the GIMP Toolkit (GTK). GRPN works with real numbers, complex numbers, matrices, and complex matrices. Numbers can be displayed in 4 different radix modes, and complex numbers can be displayed in either Cartesian or polar form, in decimal or engineering notation.