Altium Designer(aka Protel and DXP) (15-day Trial)
Required OS: Windows XP and a powerful computer as a minimum.
Description:Commercial electronics and embedded design package. Really powerful that includes:
Schematic capture and library editor.
PCB design and PCB library editor.
VHDL and Verilog (and probably more) hardware compilers.
C to Hardware compiler.
C compiler for different cores (ARM, Microblaze, Nios, etc).
Library generator that imports data from your company IC database.Many more features.
User1: I have used this package mostly for schematic capture and PCB design. I find it quite easy and productive for manual routing, with powerful rules editor and control that help too much when placing tracks. Easy integration of schematic and PCB editor, as well as libraries editors.
User2:For all those issues related with clearances for mains and high voltages, currents, and so on, it's rule editor is really helpful, limiting the manual routing when tracks reach the limits imposed.
For regular users, hobbists and little companies, it may be totally overkill. I found that I use probably <20% of all features it has.WinAVR, AVRStudio, and FPGA free software is more than enough, and can replace this other licences.
User3:For those that have not seen the new Altium pricing model..it may interest you.. I pretty much ignored their upgrade requests over the years since Protel99 as I did not see any value in their upgrades but their recent special for a perpetual license for $2k changed my mind.
In China, the Protel99 Designer Software is widely used especially in relevant department in universities because its powerful editor.