display:inline-block
display:inline-block x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x
display:inline-block - height 150px x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

Passed: Opera 9.10~9.50 & IE8b (???)

Failed: Gecko 1.9 & Safari 3.1 (showing beside green float, known bug)

Failed: IE 5.5, IE 6 & IE 7 (due to IE/Win escaping float bug and hasLayout)

Not supported: Gecko 1.7~1.8