Black Joomla
Free Joomla Template Joomla Extensions
Joomla have a native cache and Gzip compression system, that's a good start.
Speed Cache comes over as a natural improvement of the Joomla page cache system with a lot of performance, compatibility and features enhancement.
jDBexport allows you to deliver any data from your databases (JOOMLA and others) as Excel documents directly to your users.
Write any valid SQL query in the administration of this component and combine such queries into multiple Excel worksheets/workbooks
FILEman is an advanced file manager from Joomla A lightweight, speedy and vamped up version of the Joomla media manager featuring multiple and remote file uploads, automatic thumbnail generation and easy file linking.
On the frontend it comes with a built-in image gallery and support for file download listings
MightySites allows you to run multiply sites on same Joomla installation and share database data between different Joomla sites
CDN for Joomla! - speed up your Joomla! site by using a Content Delivery Network
ARI Data Tables module converts HTML tables into powerful and functional tables with possibilities to sort, filter and paging data. It can also create different charts based on data from tables.
The extension can load data from SQL databases and CSV files.
Components Anywhere - place components anywhere you can enter text
Modules Anywhere - place modules anywhere you can enter text
Content Templater - make predefined content.
Cache Cleaner - clean cache fast with 1 click.