Recently I have been reading about the UNIX philosophy for writing programs and applications. 
Their approach is to create small, simple programs (exe files) that can be flexibly composed using a scripting language. Here’s an example: ls is a program that lists the content of your current folder, sort is a program that sorts its input. Most scripting languages have a pipe ( | ) operator. We can use pipe to send the output of the ls program into the sort program:
ls | sort
That results in outputting the content of your current folder, in sorted order.
The UNIX people have been following this kind of assemble-from-small-programs approach for decades and it has been phenomenally successful. Many of their programs were written in C. But today a lot of their programs are written in Python . A really awesome thing is that C programs and Python programs can be mixed-and-matched. I wanted to see how this works so I wrote a simple Python program, mesg.py, which outputs a message (Hello, World) and a simple C program, id.c, which reads input and outputs it. The two programs are completely independent (two exe files). Then I used a scripting language to compose the two programs:
mesg | id
That results in outputting the message.
In general, with this approach we can compose any number of programs:
A | B | C | …
Each program can be written in Python or C (increasingly programs are written in the Go programming language).
Interested in learning more about how I implemented my mesg-id application? See here .
 These are fantastic books: (1) The UNIX Philosophy by Mike Gancarz, and (2) The Art of UNIX Programming by Eric S. Raymond.
 See this Stack Overflow question: Modern-day Unix tools are written in what programming language? (http://stackoverflow.com/questions/30830759/modern-day-unix-tools-are-written-in-what-programming-language)
 I initially implemented both the mesg program and the id program in Python. I’m a Python newbie so I asked a question about this on Stack Overflow: How to compose Python exe programs using pipes? (stackoverflow.com/questions/30956979/how-to-compose-python-exe-programs-using-pipes) Later I implemented the id program in C and then used a scripting language to compose the Python mesg program to the C id program. This is a very nice way to write applications!