 Hi everyone, I'm Justin Florey and I'm guest featuring for this week's opensource.com top 5 from March 31st. In this week's top 5, we highlight VI mode editing, teaching programming with scratch, command shells, DIY smog sensors in Germany, and how to harness open source powers for humanitarian efforts. Coming in at number 5, open source job opportunities grow at crisis groups. Learn how you can use your open source skills to make a difference in the world. Kate Chapman talks about how open source powers can be used for good with emergency humanitarian situations and development opportunities across the world. Coming in at number 4, how to build a smog sensor with an ESP8266 microcontroller. A city in Germany is developing their own IoT sensors to measure air quality to help combat the smog problem. Haiko Rupp breaks down what's going on in Germany to combat air pollution and how you can even build one on your own. Coming in at number 3, which Linux command shell do you prefer? Linux command shells are almost as hot of a topic as text editors among Linux users. This week we asked opensource.com readers which command shell they preferred. What did over 1600 of you have to say? Coming in at number 2 is the scratch today like the logo of the 80s for teaching kids to code. Teach your kids or students about programming with the turtle and the cat. Anderson Silva shows us how this small side project from MIT mirrors the same effect that logo had on early programmers of the 1980s. And finally, coming in at number 1, using the VI mode in your shell. Get an introduction to using VI mode for line editing at the command line. Fedora contributor Adam Miller teaches you to borrow VI keybidings to use inside of your command shell. And lastly, as an honorable mention for this week, how to write a web service using Python flask. What if you could write your own web services? Tom McLaughlin gets you started with this tutorial. Enjoy this week's top 5, opensource.com.