SEYDOGGY  For the first time in a while I had cause to use trig but couldn't find my proper sci-calculator. This worked like a charm. Thank you.  
(Version 1.0.27)

ZOOLOO  Since I've encountered ridiculously incorrect results with Calculator.app recently (see e. g. http://jadickinson.co.uk/2008/08/13/log05-and-the-os-x-calculator ), I am looking for alternatives that actually let me calculate (correctly, that is) and maybe even provide more functionality.

When I found SpeedCrunch at first, I was stunned by the range of functions and constants implemented therein. Also, it provides remarkably convenient I/O. There was a temptation to just stick with SC, but luckily, I went on and discovered Magic Number Machine.

Math:

A interesting difference in SC's and MNM's feature set is matrix support. Whilst SC doesn't support matrix calculations, MNM allows to deal with matrices in a dedicated drawer. Their elements might even be complex numbers (see below). However, matrix support is hardly integrated in the main workflow. A mature matrix calculator would let you use matrices about anywhere you'd use ordinary numbers, like in exp(A), sin(A^B) and so on, with A and B being matrices. In NMN, there doesn't seem to be much beyond finding determinants and inversion you could do with matrices, so I wouldn't consider NMN a "matrix calculator".

On the other hand, Magic Number Machine's consistent support of the complex domain already makes it an excellent choice for many tasks. Aside from the few functions (like !) that are not supposed to take complex arguments anyway, I couldn't find one that doesn't. Stuff like exp(sqrt(ln(-1))) simply returns the result, whilst SC fails at terms as basic as sqrt(-1) - it can't do complex math at all.

Compared with SC, MNM's choice of functions isn't quite as rich, but it's a good selection. According to the author's help pages, you even may add your own function definitions in case you need more.

A minor flaw I found is, (some_term)! sometimes throws an error even if some_term exactly evaluates to an integer. Example: (2^3)! vs. (2*2*2)!

GUI:

The overall look & feel of MNM's frontend is clear, well arranged and intuitive. The only two complaints I have so far:

(1) The formula editor needs some getting used to. Matching paranthesises are not highlighted. Setting the cursor at a certain point in the input line is often difficult to impossible, because cursor keys are ignored and so are mouse clicks, unless you manage to hit some rather tight and secret spot. So, you end up deleting everything backwards to that point, insert or change there what you wanted to, then type the rest again.

(2) The existance of keyboard shortcuts for all buttons is a good thing. I wish they were customizable though, as some of their predefined assignements feel somewhat odd to me. E. g., the shortcut key for "to the power of" isn't "^" but "Y".

These two flaws aside, I find the GUI definitely more appealing than the one of SC.

All in all, I'll probably keep both. SC for larger terms or more exotic functions, MNM for everyday calc and complex math.

(2^3)! gives "no number".   
(Version 1.0.27)

DANWAY  The application consistently crashes when you resize the window to the smallest size.  
(Version 1.0.26)

MIGUEL  Awesome program; it served me well through my physics and calculus clases. I particularly love the way expressions are nicely formated in the big screen; order of precedence is shown beautifully. So complex expressions look beautiful. Editing could be better though.

It'd surreal if the output could be edited like real text.

Also I'd change the way resizing shows or hides buttons.

Easy of use I rate as 4, but there is tons of potential for innovation.

Overall it's a must-have calculator for both casual and pro use. I replaced Apple's sucky calc un a breeze.  
(Version 1.0.22)

FROMEOUT11  Fantastic program, great to have when I can't find my TI-89...although derivatives and integrals would be a fantastic addition  
(Version 1.0.22)

BIRCH09  one problem

0/0 is undefined...

0/0 does NOT equal 0

please correct and update  
(Version 1.0.22)

ANONYMOUS  great freeware  
(Version 1.0.11)

ANONYMOUS  Very nice, but I got hooked on RPN while in engineering school, and I just cannot use a calculator without it...  
(Version 1.0.11)

ANONYMOUS  great app. does everything you could need a scientific calculator to do, and the interface is clean and easy to use. No problems with stabilty either!  
(Version 1.0.11)

BIRGIT  Thank you very much for this wonderful software! I love the shortcuts!  
(Version 1.0.11)

BRIAN  Very nice software! I love having all the constants within easy reach and the ability to paste. Nice sense of humor in the help section, and I like the list of calculators which can complement this one as far as features.  
(Version 1.0.11)

WMSHARP  Release 1.0.11 corrects the bug mentioned below, so the application now gives the correct result for all cases I tested. MNM will be how my preferred calculator for scientific work. Thanks to the developer for the quick response!  
(Version 1.0.11)

WMSHARP  While I like the interface of MNM and the useful selection of physical constants, I quickly found a bug that makes the application nearly useless. If I choose scientific notation with six significant figures and then multiply a very small number, say 1 amu = 1.66054x 10^-27 by a much larger number, say 1.000000, MNM gives the product as 1.00000 x 10^-25, rather than the correct value 6.47611 x 10-26. The MNM result is accurate to one significant figure, not six.   
(Version 1.0.8)

PASSINGBY  this application probably one of the best alternative Calculator.app (from Apple). It's probably more useful to ppl who like to use a scientific calculator than a normal one. The ability to few the whole calculation is very nice although typing 5/9*3 resulting 5/(9*3) instead of (5/9)*3 (Is this some kind of glitch?). Navigating the equation is quite hard using mouse.

Suggestion: There should be 2 kinds of display (or 3 kinds with the result). First is the normal typing and second is how the equation of the typing looks like (Similar to Equation Editor of OpenOffice or StarOffice).  
(Version 1.0.8)

ANONYMOUS  Nice ap, but...

1. - I had difficulty (often impossible in some circumstances) navigating the cursor within the equation (i.e., to add parentheses). Using the mouse instead of the arrow keys was a bit more useful, but I was still unable to insert what I wanted were I needed it.

2. - Unable to find how to change the defaulted 12-digit precision.

3. - Graphing usability is not intuitive (I never could get ANY sort of graph. The typing of variables resulted in the insertion of (unwanted) constants.

4. - The "Help" which goes to an online webpage is of little use unless you want keyboard shortcuts.

Conclusion: Unless you need the graphing abilities, I'd highly recommend the Calculator supplied by Apple. Place it in "Advanced" view mode, and turn on the paper tape. The paper tape is FULLY and EASILY EDITABLE!!! Although the resulting text is not standard mathematical notation, it IS easily copy/pasted into spreadsheets as well as editors such as AppleScript for those wishing to create customized programs and complex functions.  
(Version 1.0.5)

ANONYMOUS  I love it!!

Would be perfect if on my powerbook I could use the "fn" - key with uio,jkl for 456, 123. Until now I always get a double keystroke:e.g.: with "fn"-u: 44 instead of 4.

For the rest it is really increadible, what this application does!! Thank you.  
(Version 1.0.5)

ARIE  I have been looking for a long time for a simple calculator that handles hex numbers too.

MNM works just fine and it throws in a lot more. Very well done Matt, Thanks!

Just one little thing: I wish the font size could be adjusted. I'm getting older and need to strain my eyes to read the SHFT and OPT functions.  
(Version 1.0.3)

WINGMASTER  Simply Perfect  
(Version 1.0.3)

ANONYMOUS  It still downloads as code to my browers and not as a program to my desktop. Sorry.

Mike  
(Version 1.0.2)