There's also Calbe R09, which is closely related to Agfa's Rodinal. (Agfa
was effectively split after WWII, with the modern Agfa Rodinal being one
derivative of the pre-WWII Rodinal and Calbe R09 being another. Rumor has
it that Calbe R09 is closer to the pre-WWII Rodinal than Agfa's recent
Rodinal.) Dilutions and times with Calbe R09 are slightly different than
with Agfa Rodinal, but results are reputed to be difficult or impossible
to detect. In the US, Calbe R09 is available from J&C:

http://www.jandcphoto.com

They're out of stock at the moment, but IIRC they expect a shipment Real
Soon Now. E-mail them for details.

You can also, as others have suggested, find formulas for "Rodinal-like"
developers online and in books. It's fairly simple to mix, but it requires
you to handle sodium hydroxide (lye) or potassium hydroxide (similarly
caustic), depending on which formula you follow. Be sure to read and
follow the safety notes. The toughest ingredient to find will be
para-aminophenol hydrochloride. Check Photographer's Formulary
(http://www.photoformulary.com) for that.

As to APX 100, I've not used enough of either to comment personally, but
I've seen claims that Fomapan 100 (available from J&C or Freestyle) is
similar in overall "feel" to APX 100. I wouldn't suggest buying a dozen
100-foot bulk rolls on the basis of this nth-hand information, but it
might be worth buying a few 36-exposure rolls to check it out.

Another option is Rollei Retro 100. I'm foggy on the details, but I think
this is a film based on the APX 100 formula but manufactured elsewhere on
a different base. It's a new product, and I'm not sure where you might
find it (if it's even available in quantity yet; I think it might still be
in "beta testing," to borrow a phrase from the computer world).

UC, maybe you're right, maybe not, but anyway, let's respect other people's
taste, be it good or bad. In case somebody really likes the look of APX100
in Rodinal (I liked APX much better in Acutol), and as stated in other
posts:
1) Fomapan 100 is very similar to Agfa APX100
2) Adox APH09 (the late Calbe R09) is based on the pre-WWII Rodinal formula.

If you do not wish to mix your own Rodinal (wich is 1-not that much cheaper
than buying a ready-made bottle and 2-potentially dangerous if you're not
familiar with mixing chemicals!) you can order Adox as well as Foma from
www.fotoimpex.de.

BTW: why mixing yourself: if you dilute APH09 1+40 and use this one-shot it
only costs 0,07 ? (0,08 $) per film.

Like Rodinal, APH09 is a liquid, has a very long shelf life, is one-shot,
creates grain and edge sharpness and wonderful tonality. Acutol does the
same + less grain and a bit more filmspeed.

Jan

PS: I have _NO_ interest in promoting above products nor supplier, honestly!
I only wish that, when the big fellows quit for the more lucrative digital
commerce, ongoing demand for their products can keep the smaller ones up and
running. Say amen with me please ;-)