Svelte, the framework that runs at compilation time has been hot for more than one month and is back at the first position.

At position number 2, Ola is a library created by our friend Francisco Presencia to interpolate numbers. Given an initial value and a target value, it allows you to update smoothly the values over time.

The API is very simple, it works in 2 steps:

• You start by creating an instance of Ola object that wraps the value(s) to track, setting the initial value(s) and how much time the transition will last
• You set the target value(s) using the set method

For example the documentation shows how you can move smoothly an object on the screen, following the mouse clicks, by interpolating its position.

2 points that make Ola great:

• It works lazily: the value at any time is only computed when you read it
• Compared to other contenders like Tween.js animations are super-smooth, there is no “harsh corner” if there is an update while a previous transition is still ongoing, as the author says.