LampCMS open source XSLT based content management

Lampcms is a blogging and image hosting CMS.
In case you don't already know, LAMP is a common acronym for Linux, Apache, MySQL, and Php
That's exactly what is required to run our CMS, except that it will also run on Windows and will also work with other databases like PostgreSQL or Oracle or even Sqlite which is now a part of php, so if you have php, you have sqlite!
From one of the best php programmer comes a CMS that make use of the best of what php has to offer.

Support for posting regular blog post or 'announcement' or 'sticky' post
Setting the 'weight' or post. Posts with higher weight will appear higher up in the list of posts, even if they are made earlier than other posts.
RTE editors for new posts and for comments.
Upload progress bar for file uploads both for image uploads as well as uploads of 'attachments' to blog posts.
Transparent Data caching. Our cache class supports 2 types of back-end cache memcache and memcached.

We plan to add support for other types of cache like APC and a lite file-based cache system that will work without memcache and without APC extensions.
Transparent caching means that when you request the data (like the result of SQL select), it will fetch it for you, looking in cache first, then if data is not available in cache (or if cache is not available at all), it will then retrieve data from the database. This is good news for those who don't have memcache installed because the system will still return your results, just without using the cache. This means that memcache extension is optional if you have it, great, if not, the CMS will still work fine but will just make more calls to database.
We also store the first 'n' blog posts in the regular static .rss file, so when someone accesses your home page that rss file is being used as input, saving a call to database. The file with your profile and preferences is also stored as a static xml file, so another call to database is saved! Don't worry, these rss and xml files are automatically updated when you edit your profile or add a new post to your blog!
Switch account - a user can have more than one account on the system, then instead of logging out and then logging in with a different account, a user can login just once then use 'switch account' form to instantly being switched as a different user.
This is very helpful when user wants to have more than one blog each with a different account name.
'Email address check'. The registration form waits for bounced email right after the new user submitted his registration. If bounce comes back within 30 seconds (most bounces come back within 10 seconds), then an error message is shown to the user. This is useful if user's email server blocks emails from your server for any reason or if user's email box is full or temporarily suspended. This way a user will know right away instead of waiting for his registration email which will never come.

Image hosting with albums
Support for password-protected albums and X-rated albums.
Full support for EXIF data extraction from images.

Support for sub-domains like username.lampcms.com
Admin can turn this feature on or off.
Support for SEO urls' but admin can turn it on/off
The support for SEO type of links requires mod-rewrite on your apache server.
Don't worry, if you can't configure or can't use mod rewrite, you just turn off SEO links and site will still work
only the links will look like this (example)

yoursite.com/index.php?a=personal&uid=1234

If SEO feature is ON but sub-domain (virtual hosting) is off, the personal pages will look like this:
www.yoursite.com/user1234/

with sub-domains on the personal pages will look like this:
user1234.yoursite.com

Configurable user options like number of items per page, pagination on top/bottom/both,
Threaded replies with option to indicate which level of replies gets expanded and which collapsed.

Ajaxification of most forms forms will work with or without javascript.
Users can upload avatar. Uploaded avatars are resized into 3 different sizes: regular, square and tiny square.
Users can select the layout navigation on right of left.
Users can edit styles visually, without touching the .css file.
Multilingual new languages can be added.
Attachments in blog posts images are automatically resized, other attachments are displayed as attachment and can be downloaded.
Support for anonymous comments with use of captcha. Admin or site owner can allow/disallow anonymous comments.
Blog owner can close post for new comments.
Security: forms with tokens, passwords hashed (and salted), brute force detection multiple failed login attempts will cause the lockout for specified number of minutes, forcing the user to wait for awhile before trying again,
Data filtering all input as filtered as it comes in from the form. Only the allowed datatypes go through. Only the allowed named url parameters will go in. So you can't just append any extra param to url it would not work!

GeoIP module records ip-based geo location where a new user came from, where a post or comment came from. This can later be used to generate a map application to show where messages or images were coming from.
Im sure there are more I could have said about this CMS, maybe Ill update this post later if I remember some other cool feature it can do.