SimLib4Visio have many mathematical and electro-tech. blocks (shapes):
summator, integrators, unitDelay, transferFunction, trangleWave,
gausian, multiplexer, ..., R, L, C, E, J, NPN, nMos, VD, VZ, OA, ...
User can use it, wire it, set parameters, and start simulate behavior.
Oscillograph's will demonstrete rezults.
User can use SimLib4Visio to publish model in Internet.
SimLib4Visio generated interactive HTML-code (javaScript).
See
http://model.exponenta.ru/k2/doc/tt_0002mode.htm (russian)
this page will install ActiveX-element - mathematical kernel K2.SimKernel
(< 200 KB)