Zooming is a dependency-free JavaScript image zoom library that offers two-step scaling with smooth animations. In addition, it can automatically zoom into high resolution image if supplied, which was not supported by any image zoom library as far as I knew.
I built this library primarily to improve my understanding of JavaScript. Along the way, it became a somewhat popular (1k+ stars) open-source project on GitHub. It was my very first serious open source project and I devoted a lot of my time and effort working on this project.
Building a library working correctly across different browsers is certainly not easy. For example, it took me a lot of effort to fix image flickering in Firefox.
Most importantly, creating and maintaining open source software has taught me invaluable communication skills and deepen my understanding of Software Engineering. If I were to design the library differently, I would make it more extensible so other developers could easily include their own features via plugin mechanism.