Theseus – Backports iOS 26 Liquid Glass UI to iOS 13+

Summary: Theseus is a lightweight Swift Package that recreates iOS 26 Liquid Glass UI effects—refraction, depth, and highlights—on iOS 13 and later without relying on new OS features.

What it does

It rebuilds modern glass UI effects piece by piece and functions as a drop-in replacement for UIKit and SwiftUI TabBars.

Who it's for

Developers targeting iOS 13+ who want to implement Liquid Glass aesthetics on older devices.

Why it matters

It enables modern glass UI effects on legacy iOS versions lacking native support.