Slashdot doesn't have table support, so it's hard to do side-by-side well, but:

JPEG XL advantages:

Licensing:

JPEG XL: Fully royalty-free (Open source / Apache 2.0)
HEIC: Proprietary patent minefield (MPEG LA, Advance, Velos; royalties apply)

Legacy JPEG Migration:

JPEG XL: Lossless, reversible bitstream transcoding (~20% smaller); fast enough for real-time web servers
HEIC: Lossy re-encode only (generational quality loss; cannot reconstruct original JPEG)

Fine Detail & Textures

JPEG XL: Retains sharp text, fine lines, subtle textures, and film grain
HEIC: Video-derived coding (HEVC / X.265). Tends to smooth out high frequences and smudge grain.

Software Encoding Speed

JPEG XL: Extremely fast; highly parallelized SIMD architecture
HEIC: Exceptionally slow and computationally expensive in software

Software Decoding Speed

JPEG XL: Fast, lightweight multi-threaded CPU decoding
HEIC: Heavy CPU overhead (without using hardware acceleration)

Progressive Rendering:

JPEG XL: True progressive decode; smart saliency algorithm to focus bandwidth on critical details first.
HEIC: None; full file must be received and decoded before display

Lossless Compression
JPEG XL: Dedicated modular mode; vastly outperforms PNG and WebP
HEIC: Ill-suited; you basically have to try to do lossless compression with an inherently-lossy format

Bit Depth & HDR

JPEG XL: Native HDR; up to 32-bit floating point per channel
HEIC: Typically capped at 10-bit or 12-bit integer

Max Dimensions & Scaling

JPEG XL: Up to 1B x 1B; efficient viewport/crop loading without full decoding
HEIC: v5.2, 4096x2160; v6.2: 8192x4320; a tiling hack allows up to 16384 x 16384

Channels & Color Spaces:

JPEG XL: Arbitrary color spaces (hyperspectral); unlimited extra channels (alpha, depth, thermal, masks, CMYK, etc)
HEIC: Rigid container; limited auxiliary channels and standard video color spaces

HEIC advantages:

Rollout / acceleration:

JPEG XL: no dedicated hardware acceleration (thankfully, it's not as important because it's so much more efficient). Software adoption still rolling out.
HEIC: Hardware silicon (ASICs). Default capture format on modern iOS/Android; native capture in Sony, Canon, and Nikon cameras

Video:

JPEG XL: Supports animations (GIF/APNG replacement), with some optimizations** (it's not just a series of stills), but lacks the full set of optimizations that a proper video codec has.
HEIC: Container naively pairs full HEVC video tracks and audio with video.

** - JPEG XL can store up to 4 reference frames in a buffer, with multiple blending modes from the references (add, replace, multiply, etc); has subframe bounding boxes ("dirty rectangles") for when only part of a frame changes; invisible frames; modular deltas (differences between frames); etc. However, it lacks motion vectors (e.g. detecting a feature drifting across a scene and simply having to encode "move it" (followed by any needed deltas). So it's great for "GIFs", but if you wanted to encode a full movie, it'd be significantly larger than e.g. HEVC.

Look, I use HEIC, but JPEG-XL is just better.

* Royalty-free
* Lossless transcoding of legacy JPEGs to immediately reduce their sizes by ~20% (fast enough that you can have webservers do it in realtime)
* Better fine detail / high frequency data representation for the same bitrate. HEIC was designed for video and simply is not as good at stills.
* Faster decoding
* MUCH faster compression
* True progressive decoding - and not old-school blocky progressive decoding, but using a smart algorithm that restores coarse detail (particularly focusing on parts of the image that the eyes immediately focus on) first, then progressively adding in finer detail that the eyes take more time to notice later.
* Vastly better lossless compression
* Better colour depth and native HDR (up to 32 bit per channel)
* Up to 1B x 1B pixel images (again, useful for scientific and engineering applications), with efficient loading (don't have to load and decode the whole 1B x 1B image at full resolution to view it)
* Arbitrary colour spaces - you can even use it for scientific hyperspectral imaging. You can include e.g. alpha, depth maps, thermal data, selection masks, etc etc.

It's just a better format for stills. It's annoying that it's taken this long to get support to take off (because it takes ages for most people to update their browsers), but I'm really glad that it's starting to.

This. No good game was ever created from a single prompt. Not to an AI, not a human development team. Every single person writing those damn "look which game my AI built from a single prompt and $x in tokens!" postings is a newbie and almost certainly has never actually shipped a single game.

Game development can be summed up as endless iterations. Every system you build, every visual you create, every sound, text, button, movement, weapon, skill, powerup needs polishing, refinement and changes. It is never, never good enough the first time.

No it is not, but it IS a very successful platform for a specific subclass of games. If I were in it for the money, I could probably AI refactor some of my earliest games and publish them on Roblox and make a quick buck. If your thing is the kind of games you played on your C64 back in 1793, then Roblox got you covered. Well, if you ignore the scams and money-grabbing.

*sigh* I wish Unity would actually complete some of their dozens half-finished sub-systems instead of constantly chasing the latest trend. It's become really, really annoying. The engine used to be really good. These days, it falls apart if you look at it the wrong way, and at least from the responses to my bug reports it's clear that fixing issues is way down on the agenda.

Maybe this is their attempt to regain grounds in the indie game market - the very market they pushed away by focussing on AAA requirements for years and ignoring the single devs and small teams. If so, I can already tell them that it won't work. We collectively laugh about all the "look what my AI built for me from a single prompt" postings on reddit, where people proudly show off some AI slop that would get them last place at a game jam.

Their AI efforts so far: Tried to build and sell their own AI tools, to a collective yawn from the audience. Built a barely-working MCP server, then deprecated it before it was even finished in order to push a CLI interface to the editor instead, which only works if it's run as the same user as the editor on the same machine. And completely ignores every single advise on workflows and good development practices you can think of.

Unity, I love your engine, I despise your management. Please return to when you were actually good and stop chasing butterflies.

The need for them came from relativity, but the atomic clocks needed to be able to handle such fine corrections are based on the hyperfine transition of 133Cs. You're not getting very far on atomic clocks without particle physics

Okay Felicia.

Sounds like Newton. Long tradition, I guess

Let me clarify. Kids were waiting for buses in the dark. The reflective dots were being given out gratis by many businesses in order to make the kids more visible on the side of the road. Most kids in the US leave school by 3 PM. Itâ(TM)s not dark at 3 PM. If theyâ(TM)re leaving later than that, theyâ(TM)re getting picked up in a car. The only thing that has changed in 52 years is now we have a president who thinks you have to climb up the outside of a clock tower to move the hands on the clock twice a year. Stick to standard time year round.

"Okay, nuclear power. Yeah. Yeah, they did give us that. That's true. "

"And industrial-scale superconducting magnets!"

"Don't forget GPS satellite relativistic corrections!"

"And radioisotope therapy!"

"Electron beam therapy?"

"World Wide Web, wasn't that created by particle physicists?"

"Yeah, they did do that."

"Capacitative touchscreens too, you know."

"All right, all right, FAIR ENOUGH! But APART from computers, telecommunications, nuclear power, PET scans, MRIs, satellite communications, superconductors, radioisotope therapy, electron beam therapy, heat-shrink tubing, cargo and baggage screening, smoke detectors, muon tomography, capacitative touchscreens, and the World Wide Web, WHAT HAS PARTICLE PHYSICS EVER DONE FOR US?!"

"Synchrotron light sources for drug discovery?"

"Oh, drug discovery?! GROW UP!"

Yeah, what has a better understanding of particle physics ever done for US, huh??? ... ...

_ ...........

if this were true it would not be possible for the system to read the watermark.

You confuse "invisible to humans" with "invisible to statistical analysis". Humans can't, for example, see the difference between metameric colours. Statistical analysis can. Humans can't see minor drift at scales where Brownian motion dominates. Statistical analysis can. Humans can't see the difference between background disease rates and new rising threats. Statistical analysis can. On and on. Statistical analysis is a far more powerful tool than human perceptual abilities.

this is also a lie. Identical thoughts must be expressed identically, otherwise they are, in fact, *different* thoughts.

I literally gave an example above. If you saw "picked a mango", "selected and picked a mango", "from within the tree, picked a mango", you would never think there was anything going on in the choice, and it isn't going to change the story one iota.

The target audience for this particular rule of the AI Act isn't the producers or users of AI. It is the consumers of content that might be AI generated.

And frankly, letting people know if they see AI content or not is a fair thing to ask.

Fun fact: The EU AI Act considers this. It makes a difference between "AI generated" and "AI modified".

But it's hard to put this into the type of watermarking they are using. Because if you generate a text and then change a few things here and there what you are doing is degrading the watermark. But since the watermark is probabilistic, it's hard to tell if it was a weak watermark from the start or if it was degraded.

US did year round DST for a year. It was a disaster. Kids walking into school buildings in the dark.
We would get free reflective dots at McD and other retailers to put on coats, shoes, bookbags.

("It actually makes RAM needs worse" -> "MoEs actually make RAM needs worse")