Roadmap / Exponential Velocity roadmap

Exponential Velocity roadmap

Exponential Velocity is a persistent PHP application server based on the Qbix engine. Its workers load Exponential once and keep it in memory, so each request skips the start-up work. Public pages are answered from its own response cache in a fraction of a millisecond. The current release is Exponential Velocity 0.0.4.57 (29 October 2026). The 0.0.4.x line had 54 releases this year. It runs on PHP 8.0 and later.

Delivered in 2026

  • Delivered: persistent workers. A worker keeps the loaded kernel, the settings and the compiled templates between requests, starts each request clean, and runs clean-up handlers and shutdown functions for each request. A watchdog keeps the server up when a restart is cut off.
  • Delivered: the response cache. It answers repeated public requests inside the server process, with conditional requests, ETag, stale-while-revalidate and compressed storage, and can be paused for maintenance.
  • Delivered: the HTTPS certificate subsystem. Certificate sources per mode, a self-signed fallback, and certificates swapped while the server keeps running.
  • Delivered: a Debian-style configuration layout under /etc/vc, organized like /etc/apache2: base settings, ports, and available and enabled conf snippets, modules and sites, with tools to enable and disable each.
  • Delivered: one-command deploys. exp:velocity deploy runs every step of a PHP change in order: autoloads, caches, a check of every changed engine file, a graceful reload of the web server's PHP, a Velocity restart, and the response cache. It stops at the first failure.
  • Delivered: opcode cache and profile settings for the workers, with the opcode cache sized for the help center.
  • Delivered: release builds in every form people install. The Composer package, deb packages for Debian 12 and 13 and Ubuntu 22.04 and 24.04, rpm packages for Enterprise Linux 9 and 10, Docker images for amd64 and arm64, static binaries with PHP built in for Linux, macOS and Windows, and a phar. Every release carries SHA256 checksums.
  • Delivered: a dashboard and a control panel in the browser, a scheduler, WebSockets, Server-Sent Events and rooms, static files and images, discovery and federation between servers.

In progress and next

  • In progress: smarter deploys. A deploy clears only the caches that a change affects instead of every cache. This is landing now.
  • Next: warm-up. A restarted server loads the pages that matter before it takes traffic.
  • Next: restarts without dropped requests. The new workers take over while the old ones finish the requests they are answering.
  • Next: packaging for production. deb and rpm packages in package repositories, so apt and dnf install and update Velocity, with hardened systemd units.
  • Next: a 1.0 line with a stable configuration and a stable application interface.
  • Next: upstream contributions. Generic engine improvements go back to the Qbix engine as pull requests. Features specific to Exponential stay in their own distribution layer, so the rest of the engine can be shared unchanged.
  • Considering: more measured performance comparisons with other PHP application servers, published with the scripts that produced them.

Help wanted

  • Run Velocity in front of a copy of your site and report pages that behave differently than under PHP-FPM, in the issue tracker or the Velocity repository.
  • Test the deb, rpm and Docker builds on your distribution and tell us what the systemd units should do.
  • Review the engine changes we send upstream to Qbix.
  • Discuss in the Developer forum.