Free Circuit Design Software

Circuit design programs such as National Instruments, MultiSim 11 are great tools, but costs a lot of money and includes many features that most people, especially, digital electronics enthusiasts, novices, and students would never need. After a few months of searching and experimenting, I was able to compile this list of completely free circuit design software. I can promise you all of the following free alternative circuit design programs on this post are excellent programs. LINKS FOR ALL SOFTWARE ARE INCLUDED!

1. Multimedia Logic

A screenshot of a circuit built with MMLogic.

Softronix's Multimedia Logic
MMLogic, the interactive logic simulation software is both, free and open source! Since this program is open source, that means that its users can create their own modifications of the application to enhance the features it already has. If you are a programmer, this option should be even more appealing because you can see all of the source code for the program. Also, this program is very easy to navigate because it contains generic pieces such as individual AND-gates instead of a 74xx08 integrated circuit and has an easy to use Design Palette for selecting, editing, and placing components. A lot of fun! If I had to pick a negative about this program, it would be that there isn't so many pieces and options available in the standard library you use upon download.
Go to download page: Multimedia Logic v1.4

Lessons and projects for MMLogic.

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2. MultiSim 8 - Student Edition (FREE)
The student edition of Multisim has distinct differences from the professional (payed for) version of the software. The Differences. Multisim is a very professional program, but contains many parts even I have not touched. Compared to MMLogic (above) this program is much harder to learn to use because it contains so many resources. MultiSim 8 has the largest amount of resources and components than any of the other circuit designing software on this post.


Go to download page: Multisim Academic Evaluation (Multisim and Ultiboard)

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3. Logisim

Snapshot of a Logisim project

Logisim is similar to MMLogic (the first item) in appearance and control, but has a larger library of content for you to use than MMLogic. For example, MMLogic has only one type of Arithmetic Logic Unit (ALU) that limits you to using 8-bit length data, but Logisim has a total of 9 different ALU components that can use any bit length from 1 to 32.   Logisim is a great balance between the detailed but complicated Multisim 8 (2nd item on list), and the friendly and simplified environment of MMLogic. 
Go to download page: Logisim on SourceForge

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4. Logic Circuit Designer
Logic Circuit Designer is specialized to be used for logic circuit creation as opposed to full on electronics systems. The layout is very easy to understand and has only the absolutely necessary components you would need to create your logic circuits. The reason you may like this one over MMLogic (2nd on the list) is because the click and drag function creates wires by default, sadly, MMLogic needs 1 more button click for each connection when compared to Logic Circuit Designer. Logic Circuit Designer also allows you to specify the angle at which a component is facing. This is not available in Logisim or MMLogic.
Go to download page: Logic Circuit Designer