ATCalc is an open source and freeware computer program, and is a scientific calculator with structured programming and graphic functions; although it could also be defined as an interpreter (compiler with debugger) of structured instructions (like Pascal) of general purpose, with high level procedures and functions (with windows of data input, representation, drawing), and it can behave as a simple calculator. In this way it is a program conceived very differently to big projects such as Wiris and GeoGebra.
Programs registered at www.sourceforge.net on 09/15/2007 and searched with the keywords: Calculator (543) and Calculadora (7).
That are not open source and freeware (initial exclusion already made in the search).
That don't run under Windows.
With RPN (an alternative to the most popular: the algebraic notation).
That don't contain graphic representation and/or programming.
That are emulators of desktop calculators (Hewlett Packard, Texas Instruments).
That are explicitly dedicated to a community (e.g. engineers).
That are difficult to install: this has made me exclude several programs in Java that gave the habitual error of “Failed to load Main-Class manifiest attribute from...” (they need to install JBuilder or Eclipse, to see how the program works, ....) or written in Phyton (needs to choose a compiler, to know how it works, ...).
In this way I have not been able to try out: MathLab, qmcalc , Daisuke-Edit , Math Eclipse Plugin.
Some programs could not be installed, due to internal error and some of the .NET programs, after installling Framework (with the consequent wide space occupation in disk), gave the error that Framework was not loaded (requesting an old version of it).
ICalc: contains programming but with a non-friendly environment, needs a lot of dedication, since the level is very high.
Precise Calculator: very simple programming.
Pc-Calculator: on DOS (non-friendly), not structured programming.
Clearly a cut above the rest: EasyFunktion and GraphCalc.
With less quality/features: MTAC - More than a calculator, ctCalc , YAMM - Yet Another MATLAB Mini, FullGraph, QuillEdit, Graphical Calculator, WeissCalc (needs .NET).
I have not found programs with both qualities, although, I have not been able to install the programs mentioned previously (MathLab, gmcalc) which may have both qualities.
It has a structured programming environment (like Pascal).
Representation not only of functions, but also of drawing; with display, import and export of images; calculations have more than enough images.
Adaptation (changing the font) for people with visual deficit.
Very flexible: in spite of its great power, if you want, it can occupy a minimum space and be used as a simple calculator with algebraic analysis.
With 4 languages: Catalan, English, Spanish and Portuguese.
Important helps (examples, contextual and directly for functions/procedures), and for the 4 mentioned languages.
It doesn't have a version for a free environment (Linux).
It doesn't have access to databases (although it has import/export functions of files with fields separated by tabulators, and import/export from the clipboard).