It seems that if I compile apache-1.3b5 (and 1.3b3) with 
php3.0b4 under Solaris 2.5.1, the apache server goes into
a spin and refuses to serve connections. The browser
symptoms are that the Netscape icon continues to animate
and the cursor stays as a watch for ages. The server is
a Sun Ultra2 with 2x200MHz CPUs and 512Mb of RAM and loads
of mirrored fast disk.

apache-1.2.5 with php-3.0b4 runs very fast on this beast
but apache-1.3b5 with php-3.0b4 is worse than death warmed
up.

I compiled php using the following config line:

./configure --with-apache=/archive/src/text/http/apache/apache_1.3b5

This ensured I had no extra libraries to worry about such
as gd, gdbm, msql etc. The LIBS line from mod_php3.module
is

LIBS="-Lmodules/extra -L../modules/extra -lphp3   -lm -ldl -lnsl -lsocket

I have the following modules compiled into apache

AddModule modules/standard/mod_env.o
AddModule modules/standard/mod_log_config.o
AddModule modules/standard/mod_mime_magic.o
AddModule modules/standard/mod_mime.o
AddModule modules/standard/mod_negotiation.o
AddModule modules/standard/mod_status.o
AddModule modules/standard/mod_include.o
AddModule modules/standard/mod_autoindex.o
AddModule modules/standard/mod_dir.o
AddModule modules/standard/mod_cgi.o
AddModule modules/standard/mod_asis.o
AddModule modules/standard/mod_imap.o
AddModule modules/standard/mod_actions.o
AddModule modules/standard/mod_speling.o
AddModule modules/standard/mod_userdir.o
AddModule modules/standard/mod_alias.o
AddModule modules/standard/mod_access.o
AddModule modules/standard/mod_auth.o
AddModule modules/standard/mod_expires.o
AddModule modules/standard/mod_setenvif.o
AddModule modules/extra/mod_php3.o

In my tests to narrow down the problem I tried starting
with a default apache config and then added one module
at a time. Each additional module showed no problem until
I added the php module.

I don't know if its a php problem or an apache problem so
I'll send a bug report to both groups.