At first there was Pentium I.
 

Hi:
At a given time there was Pentium I. Then came Pentium II, no matter what happened in the middle. Then Pentium III and Pentium 4. Of course each of these comprised a certain set of different models. Can the CPUs released by Intel at present be placed under the label Pentium N for some integer N? Put otherwise, is Intel still using a number following the word Pentium to identify the Pentium products or families/groups/sets of Pentium products?

While Pentium was the top of the line product back in the times nowadays it is a cheap entry-level modell. Nonetheless, there is some continuity in the naming.
After the Pentium 4 they released (under pressure from AMD's Athlon64 X2) the first dualcore Pentiums with cores derived from the late Pentium 4 core (Prescott), codenamed Presler. Those Pentiums were codenamed Pentium D (respective Celeron D for the cheap models) . After that Pentiums weren't available for some time, Intel changed to the core naming scheme with the Core 2 Duo/Quad, but ion 2009 they reintroduced the Pentiums as low-level CPUs, named Pentium E on the desktop and Pentium T for mobile machines. These CPUs were cut down Core 2 CPUs. Surprisingly, the Nehalem (first core i7) based Pentiums were not named Pentium F but Pentium G and are still named like that for newer architectures (Sandy Bridge, Ivy Bridge).

By the way, all this information is easily available on the Wikipedia page for Pentium, a short websearch should have lead you there.

That depends on your perspective.....:) Some will say that it was more like:
8080
8085
8086
80286
80386
80486
80586---at this point, they got tired of all the numbers and started using "Pentium".

The ultimate processor has now simply been labelled "Latest"---if you buy one of these, you are assured of having the most up to date technology. Further, stores don't need to keep changing their promotional media----as in: "Our computers all feature the Latest Processors.".......;)

Sorry--it's a slow news day and no-one has posted any fun programming problems......

Not really. They realized that you can't protect numbers with trademarks, so they introduced names, so that their competitors can't release CPUs with the same name.

You missed the tongue in my cheek......

Your explanation is almost certainly more correct than mine.

OK. And thanks. Having seen so many wikipedia articles dedicated to Intel processors, full of cross-references, I did not realized the was an article summarizing all of it, or part of it given what you've said. But I did a very concrete, very punctual question. Judging from your answer, the Pentium numbering ended with Pentium 4 but a new naming scheme has began using letters instead of numbers (desktops): Pentium E, Pentium G (they skipped F) and perhaps they intend to go on with H, I, ...

Quite a pity beacause I too had a naming scheme for my machines, based on the name of the processor inside. I had MACH4 (80486), MACH5 (Pentium I), MACH6 (Family 6 Intel CPU), MACH6P (also family 6 so the name reads MACH6 prime). Now I have Intel Pentium G620 Sandy Bridge and I'm trying to give the machine a name which reflects this processor name yet at the same time is consistent with my previous scheme.

I'd ignore the 'Pentium' naming now. Its pointless, and only there for marketing (and its only in the marketing now becuase of the amount of money intel threw at TV adds, etc, for the Pentium branding). Still trying to use the 'Family' naming as well? Also pointless.

Pentium 1- P5 architecture.
Pentium Pro, Pentium II and onward- P6 '(i686') architecture.

I've seen various tries at giving the newer intel CPUs iXXX (PX) naming. Its best confusing (is pentium II, III or IV 'i786'? I've seen all 3 listed as 'i786' at some time...). Intel actually does own i787, i886 etc. but has never used them.

If you want a name hat fits with your convention, try this-

MACH632i3crippled.

'32' because of the 32 nanometer manufacturing process (newer 'ivy bridge' CPUs use 22 nm). 'i3' because its based on the intel i3 series chips. 'Crippled' because hyperthreading has been disabled (standard fearure on desktop i3s).