What are yesterday's rock stars up to today? More importantly, how do they look? Ever curious and nostalgic, we decided to check in with Trent Reznor, Billy Corgan, Chris Cornell and some of our other favorite '90s alt-rock superstars to see what they're up to these days. Many have weathered the years much better than you may expect. Others, well ... scroll through our list of '90s Rock Stars Then and Now and see for yourself.

1. Trent Reznor then was the long-haired and skinny king of Nine Inch Nails.

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Now, he's a short-haired and muscular Oscar-winning composer who, in addition to leading a reconstituted NIN, fronts How to Destroy Angels.

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2. Anthony Kiedis then was rocking the long-hair look.

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The Red Hot Chili Peppers singer has since chopped his flowing mane and grown a porn-star mustache -- but he's still shirtless, still buff and still looking fine.

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3. Then: Dave Grohl in his goofier days, yucking it up with late Nirvana mate Kurt Cobain.

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Now: Grohl dons a sharp suit and skinny tie as frontman of the Foo Fighters. He's also a film director, drummer-for-hire, serial collaborator and public speaker -- and he still seems like an all-around likable guy.

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4. Billy Corgan then was a cherub-faced rocker with short, boyish locks.

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Now, the Smashing Pumpkins singer is an Uncle Fester lookalike who shaved his head for 1995's 'Mellon Collie and the Infinite Sadness.'

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5. Time has always been on Beck's side. He looked boyishly handsome back in the '90s...

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... and now, the singer hasn't aged one bit. Dude looks almost identical to his young self.

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6. Then, singer Eddie Vedder was a reluctant rock star.

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Now, the Pearl Jam frontman has aged remarkably well. If he still hates fame, he wears it better.

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7. Then, Chris Cornell was the subject of many a schoolgirl crush.

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Now, the Soundgarden singer turns more heads than ever, and his band is back in action. Does that mean no more Timbaland albums?

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8. Then, Gavin Rossdale was the pretty-boy frontman of Bush.

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He still is, although his wife, Gwen Stefani of No Doubt, remains his better half.

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9. Then, Blur's Damon Albarn looked like the prep-school grad that he was.

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Now, Albarn's fronting the reunited Blur, although he does look a little bit worse off for the wear.

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10. Courtney Love emerged as a superstar during Hole's 'Live Through This' days.

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Love, having lived through plenty, soldiers on with more than a little work to show for it, if you catch our drift.