CiviCRM Extension for high performance activity features.
It currently features a replacement for the activity tab in the summary view, and simplified reports with a better performance on systems with large amounts of activities.
Settings such as which columns to display can be configured under Administer → Customize Data and Screens → Fast Activities Tab
This extension implements a "FastActivity" tab which uses an entirely new BAO class (CRM_Fastactivity_BAO_Activity) to query the database. This is implemented in the "standard" CiviCRM format with a separate whereClause function which is not present in the original CRM_Activity_BAO_Activity class. This should allow for easy implementation of extended filtering in the future.
Requires CampaignManager extension (for campaigntree API) to search for activities of child campaigns in contact activity tab.
For Release 1.1 and above (which includes a link to "File on Case" for activities) you need to apply PR-12620 to CiviCRM core if you are using a release earlier than 5.6.