Scilab

Scilab is free and open source software for numerical computation providing a powerful computing environment for engineering and scientific applications.
Scilab is released as open source under the CeCILL license (GPL compatible), and is available for download free of charge. Scilab is available under GNU/Linux, Mac OS X and Windows XP/Vista/7/8 (see system requirements).

What is Scilab ?
Scilab includes hundreds of mathematical functions. It has a high level programming language allowing access to advanced data structures, 2-D and 3-D graphical functions.
A large number of functionalities is included in Scilab:

EAGLE PCB Desing

Schematic Editor
The goal of the schematic is to provide documentation about the design, allowing others to easily understand your design intent. EAGLE comes with thousands of pre-made parts that simplify your schematic capture tasks.
Layout Editor
You can locate your components accurately and route copper traces between them. EAGLE's Layout editor includes sophisticated features such as assembly variants, differential pair routing and much more.
Autorouter
The autorouter can be guided by adjusting its cost factors to control its routing behavior producing useful results in no time. The Autorouter protects prerouted traces giving you full control over what nets need to be manually routed and which can be routed automatically.
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KiCAD

A full Getting Started guide is included in the KiCad documentation, in multiple languages. This covers the process of creating and completing a simple project. We recommend that all new users read this first, in order to learn the basics.

Quick KiCad Summary
This is a quick summary of how KiCad functions. More details can be found in the full documentation.

Libraries
KiCad uses two separate types of library: symbols (.lib) and footprints (.pretty). Symbols are used to draw the schematic. Once symbols have been placed into the schematic, footprints are assigned to them, and then these are used to lay out the circuit board.