Oh, IE "supported" PNGs almost maliciously. If you had a True Color PNG? No problem. Paletted 8-bit? No problem. 8-but with alpha? Fine. True Color with alpha? I hope you like seeing your background color you meant to alpha out.
You had to use Microsoft's DirectX filtering CSS extensions to properly handle the alpha channel of True Color PNGs.
Not exactly, palletised png supports a full alpha channel which did not work with IE.
Though you had to work to get that as usually software would limit palletised output to GIF (if you didn’t outright have to create your pngs from gifs).
You had to use Microsoft's DirectX filtering CSS extensions to properly handle the alpha channel of True Color PNGs.