Qt Frameless Window for both Windows and OS X, support Aero Snap, drop shadow on Windows, and support Native Style such as round corner, drop shadow on OS X. Based on QMainWindow.

Provides 9-patch based drop shadow for view elements. Works on API level 9 or later.

Drop shadow effect for any widget in Flutter

Easily add drop shadows, borders, and round corners to a UIView.

Enrich your Compose UI with enhanced shadow expressions. This library offers advanced drop shadow and box shadow features.

Create Dropshadow on Borderless WinForm using VB.NET and C#

Copies images, adding a smooth drop shadow, with enlargement to accommodate. Requires GIMP.

A set of useful extensions for the Window class for WPF.

CSS-like effects brought to Java shape painting.

Like @material/elevation, but with drop-shadow instead [mirror]

image manipulation using filters

How To Style Your Website

A CSS sample of displaying scroll guiding shadows