In addition to being a PHP optimizer and caching engine, you can use eAccelerator to encode your PHP  scripts, so you can redistribute the encoded version to clients that have eAccelerator installed, without  fear of source code snooping.

As with other PHP encoding solutions, when files are encoded using eAccelerator, they are nearly impossible to decrypt using standard tools. They can, however, be reverse-engineered using debuggers and disassemblers on the PHP engine itself, but usually such an effort is not warranted by the possible reward.

Installing eAccelerator

Like APC, eAccelerator can be installed as a DSO, using the following process. First, download a copy of  the source code, available at http://eaccelerator.net/.

      Unfortunately, at this time eAccelerator is not compatible with the CGI binary version of PHP. If you
      run the CGI binary version, this section is for information purposes only.
 

Extract the tarball that you downloaded, and then go into the newly created directory:
 

                  tar -xvzf eaccelerator-0.9.3.tar.gz

                  cd eaccelerator-0.9.3

Run your copy of phpize in this directory (again, change paths accordingly):

                 /usr/local/bin/phpize 

  Then, configure the source, and build the binaries:

                  ./configure \

                 --enable-eaccelerator=shared \

                 --with-php-config=/usr/local/bin/php-config

                  make

After the build completes, install the DSOs, as root:

                  make install
 

Next, you need to provide a place for eAccelerator to put temporary files. Create an eaccelerator  directory in the /tmp folder:
 

                  mkdir /tmp/eaccelerator

                  chmod 0777 /tmp/eaccelerator

Finally, add the following to php.ini, and then restart Apache:

     extension="eaccelerator.so"
 

Configuring eAccelerator

Like APC, the default options will probably suffice in most situations, but if not, you have access to the  following php.ini directives:

Removing eAccelerator is as simple as deleting or commenting-out the appropriate extension line in  php.ini, like so:

     ;extension="accelerator.so"

To permanently remove eAccelerator from the system, delete the eaccelerator.so file from the PHP extensions directory.

      For more information on eAccelerator, visit http://eaccelerator.net.