this project is a computer algebra system. For instance, you can
- do symbolic calculation
-- expand formulas like (a+b)^3 --> a^3+3ab^2+3a^2b+b^3
-- differentiate e.g. d/dx e^(5*x) --> 5*e^(5*x)
-- solve simple equations, like a+5=3 --> a=2
-- calculate limits

- do exact calculation (with support of GMP)
-- e.g. calculate 100! exactly

and more.

Therefor, two programs are installed
- simple  -- a simple command line frontend
- (ONLY KDE 4) krunner_cas_plugin.so -- a plugin for krunner. You can type in =<your equation> in the krunner menu

the syntax is as follows

+ * - / ^                 as normal, two add, multiplicate, subtract, dividade and potentate
a b ... z                 low letters are variable names
diff(term,variable)       differentiate the term
Set[term,term1,term2]     replace all term1 in term with term2
Expand[term]              Expand the term
Factor[term]              Factors the term (not yet working)
Lim[term,variable,value]  calculates the limit of term, when variable goes to value

the project has its own rule based language, you can add new operators and simplification rules to support more things.
Look into the subdirectorys RuleParser and Regeln.

A rule looks like follows

<start term> --> <end term> ;

an example rule is

Exp[ Ln[ {x} ] ] --> x;