The 6 most popular online courses on edX, from computer science to analyzing data with Excel

In this introductory computer science course, students learn "how to think algorithmically and solve programming problems efficiently" using concepts like abstraction, algorithms, data structures, encapsulation, resource management, security, software engineering, and web development.

They will also become familiar with programming languages such as C, Python, SQL, and JavaScript, plus CSS and HTML.

Students will develop and present a final programming project to their peers.

Time commitment: Altogether, the program should take 12 weeks.

This course is part one of an introduction to computational thinking, programming, and computer and data science.

Without any prior experience in computer science or programming, you should be able to exit both with an understanding of how to think computationally and write programs to tackle problems.

The class focuses on breadth rather than depth. You'll learn about Python, simple algorithms, testing and debugging, data structures, and get an informal introduction to algorithm complexity.

Time commitment: This course should take nine weeks to complete.

If you've never learned Linux, this course offered by The Linux Foundation is a good place to start. It's taught by Jerry Cooperstein, The Linux Foundation's Director of Training.

Students will gain a flexible knowledge of Linux using both the graphical interface and command line. They will come away from the course comfortable with the tools and techniques most commonly used by Linux system administrators and end users in their day-to-day work.

Time commitment: This course should take 14 weeks to complete.

This Microsoft Excel course helps you master advanced tools for analyzing and visualizing data. Students will learn how to import data from different sources, create mashups between data sources, and prepare data for analysis.

Students will also explore how business calculations can be expressed using the DAX calculation engine and see how the data can be visualized and shared to the Power BI cloud service, among other things.

This course does come with system requirements, like Windows operating system: Windows 7 or later. You can find them here.

If this course is too advanced, or you're focused on mastering pivot tables, pivot charts, slicers, and dashboards, you may want to check out DAT205x: Introduction to Data Analysis using Excel.

Time commitment: This course should take six weeks to complete if you're spending two to four hours on it — and it'll be retired at the end of October, so only enroll if you're able to finish the coursework in time.

This course prepares students for IELTS, the world's most popular English language test, used to test the proficiency of students applying for higher education in an English-speaking country.

Students will have immediate access to over 80 hours of interactive practice materials in reading, writing, listening, and speaking. It was designed by English teaching professionals at The University of Queensland, and the verified enrollment feature just includes extra study materials.

Time commitment: This course should take eight weeks to complete, but by virtue of it being self-paced, students can take every unit or simply select the areas they need practice in before the tests.

This course is for those who want to go knee-deep in the English language style and grammar. Students will sharpen reading, writing, and editing skills by examining grammatical principles, word usage, writing style, sentence and paragraph structure, and punctuation.

The course materials include video clips of interviews with respected grammarians, as well as mini lectures, readings, quizzes, writing activities and assignments, and opportunities to have discussions with peers and assess their work.

For this reason, this course is instructor-led on a course schedule rather than self-paced.

Time commitment: This course should take eight weeks to complete.