**Added**: I found the Wikipedia article *Comparison of Computer Algebra Systems* from a link on Sage's site. Various systems are listed in tables, each identifying cost, features, etc. for each of the programs. That may help you ultimately determine what works best for YOU!

**End "Added"**

I can't speak for **hicalc** (I've not heard of it!) but IMO, a good choice would be **Sage Notebook**: it integrates a whole bunch programs: GAP, R (statistics), Pari, etc. (see more programs listed below), and you can program, as well (Python?). I'm not sure about its graphing capabilities; though it does seem to come equipped with some graphing functionality. You can create your own account if you scroll down to the bottom of the webpage linked immediately above. (You can also peruse sample "Worksheets" from "notebooks").

Another "plus" about Sage Notebook is that you can create folders, save your work, etc, on-line, and can then thus access it (when on-line again) and pick up where you left off at another time.

**Mathematics packages contained in Sage**

Algebra: GAP, Maxima, Singular

Algebraic Geometry: Singular

Arbitrary Precision Arithmetic: MPIR, MPFR, MPFI, NTL, mpmath

Arithmetic Geometry: PARI/GP, NTL, mwrank, ecm

Calculus: Maxima, SymPy, GiNaC

Combinatorics: Symmetrica, Sage-Combinat

Linear Algebra: ATLAS, BLAS, LAPACK, NumPy, LinBox, IML, GSL

Graph Theory: NetworkX

Group Theory: GAP

Numerical computation: GSL, SciPy, NumPy, ATLAS

Number Theory: PARI/GP, FLINT, NTL

**Other packages contained in Sage**

Command line: IPython

Database: ZODB, Python Pickles, SQLite

Graphical Interface: Sage Notebook, jsmath

Graphics: Matplotlib, Tachyon3d, GD, Jmol

Interactive programming language: Python

Networking: Twisted

More details available here **Wikipedia on Sage**.

See also **Sage Documentation**, where you can find tutorials, manuals, references, etc. available on-line and as downloads (e.g. pdf)...I've personally found the "help" mechanism in Sage quite valuable.