I tried to install mcrypt, and it said libmcrypt was not found. Oddly, yum seems to think it's there. Both messages at the bottom of this post.

This exists:
/usr/lib/libmcrypt.so.4.4.7

I copied it to:
/usr/lib/libmcrypt.so

Also:
vi /etc/ld.so.conf
added /usr/lib
ldconfig

Still no joy.

wget http://superb-west.dl.sourceforge.ne...t-2.6.7.tar.gz
tar -zxvf mcrypt-2.6.7.tar.gz
cd mcrypt-2.6.7
./configure
configure: error: *** libmcrypt was not found

yum list *mcrypt*
Installed Packages
libmcrypt.i386 2.5.7-1.2.el5.rf installed

The package mcrypt is available on the epel repo. That should take care of it.

Cool! That did the trick. Now what about these two?

No package mysql-devel available.
No package tinyxml available.

What version of redhat do you have? You need to turn on some of the extra channels in order to have access to some of the packages. For example, if you have the Desktop version, you need to enable the workstation channel in order to get the extra mysql stuff. For tinyxml, I'm not sure an rpm is available from Red Hat.

Redhat Enterprise Linux - OS ES 5.0
Which channel do I need to enable? And how do I do so?

I've got a C++ program I'm trying to compile that depends on tinyxml. It would be nice to not have to re-write it.. any suggestions?

You will need to log in to your Red Hat account at rhn.redhat.com. In there, click on your system host (your actual computer hostname). You should see a section called "Alter Channel Subscription". Go ahead and click on it that link. On the next page, you should see a list of channels that you can sign up. Select all that applies, but in particular, you want to select "RHEL Desktop Workstation". That should enable you to download all the extra mysql packages (including the server stuff) along with other developmental compilers. This should get you going in the right direction! Let me know how that works.

mysql-devel.rpm
- requires:
mysql-libs.rpm
- conflicts with:
MySQL-server

This is a production server, so I can't exactly remove MySQL-server

I'm looking at buying a copy of RHEL for my local computer. I see it's $349 for ES, and $80 for the basic desktop.

Either is OK, but it's silly to throw money away. Would desktop be equivalent, software-wise? Or is there a better path?

OK, I talked with Red Hat sales and they think the $180 workstation will be what I need. Thanks for you help!

Sorry, I missed your previous post. You will need the workstation edition if you plan to require support for mysql. It sounds like you will, so it looks like it would be a good choice, especially for a production server. I use the Desktop version on my home computer with no problems. Enabling those extra channels gives me all available rpms, including those from the workstation edition. However, because I only have the desktop version, Red Hat will not provide support for the workstation packages. Red Hat only supports your main channel. Hope this made sense.