Well, it is nice when your project to group and it mean not only more money, but more server resources. And if you didn't start to receive money it will be normal if you will start to search for options without increasing monthly payments.
With version 1.4, GPix have "Advaced settings" which provide you control over advanced features. You can leave them as is and GPix will work, but you can research them and choose to change for your special case.
Do you like and use SimpleXML? it is nice library for development common tasks, but have one BIG limitation - SimpleXML extension requires PHP 5. And what you will do if client have PHP4? it will be big success if client can upgrade php to version 5, but if not? There are a lot php custom solution which require PHP4 and clients don't want to spent money for upgrades or just prefer to to leave it as it, because it work.
When peoples work with Outlook long years. And it is normal for peoples to use this data in another application. In many cases when peoples choose program they can not images which requirement they will have in the feature. As result it is possible to have data in "unique" format. And when you need to change mail server you need to configure. But why man need to open dialog boxes and make mistake when hosting company are able to provide ready to use configuration file? or take outlook configuration file to fetch data from another mail server?
Main goal for GPix versions 1.4.x is integration with third party systems. GPix 1.4.0 was release with integration API. Now, this API is improved and new integration modules added.
So, if you use vBulletin, Drupal, Mambo or Joomla. GPix can handle user authentication for this systems. As result you existing user don't need separate registration for GPix. More all existing users will be handled automatically.
memcached is service which provide memory cache storage. It can provide access to cached object via network and it is extrimly fast!
memcashed pecl module is a way which can be used to access cache storage. How it work? It more complicated instead Cache_Lite, but it is fastest. This fact can be explain: Cache_Lite use file system to store cache objects.
One way to speed up web application is to lower database usage. Databases designed to provide very fast manipulation with data in files. Often developer use databases for everything and store session data, user files. This action make tables big and database server work slowly...
Why cache need to be part of optimization? - if you know what you do and how it is very fast way to lower server load. So, after load is lowered you will have time to think about logical optimization ;)
What we can cache?
logical results(which isn't design as separate functions)