Inactive users are logged out after a period without requests, using Clearance cookie expiration and a per-request refresh to keep active sessions alive.

Temporary downloads can fail in Rails 3 when send_file triggers X-Sendfile and the web server cannot read files under /tmp. Using an allowed temp directory avoids 404 errors.

Typing accented letters on dead-key-free keyboard layouts is still possible with a configured Compose key and the right compose combinations.

Rails 3 remote links can replace page content with returned HTML, restoring the Rails 2 link_to_remote update behavior through jQuery and rails-ujs.

Selenium and Launchy can trigger Firefox profile errors when Launchy opens pages through the active browser. Setting LAUNCHY_BROWSER and BROWSER to Chrome or another browser avoids the conflict.

any_instance stubbing and expectations now work in RSpec 2.6, enabling should_receive and stub on instances created inside code.

Exception tracking service for any platform with a Rails notifier and REST API, useful as a free alternative to Hoptoad/Airbrake for custom error reporting.

Hex values for the 16-color CGA palette used on Color Graphics Adapter displays in the 1980s.

Virtual date attributes in forms arrive as strings, so Rails does not auto-cast them like database columns. A custom accessor can coerce them to Date objects or nil.

Turn an unused Caps Lock into a second Escape key for faster modal editing and keyboard-driven workflows.

url_for accepts only one argument, so extra query parameters fail. polymorphic_url builds the same link and keeps additional params.

update_all can ignore conditions when :order and :limit are present, causing unintended bulk updates in Rails 3.

Non-ASCII values in HTTP headers need RFC 5987-style encoding, especially for filenames in Content-Disposition downloads with plain ASCII fallbacks.

Capybara and selenium-webdriver version mismatches can break element interaction with a private select method error. Aligning gem versions avoids the API incompatibility.

Skype messages with typos can be corrected after sending by reopening the last or any current-session message and editing it in place.

Create a file with an exact target size on Linux for testing or temp data, using dd or zero-filled writes.

Centralizing Linux configuration in a Git-backed ~/.dotfiles repository keeps settings versioned and easy to sync across machines.

Run a tiling window manager inside GNOME to keep GNOME services while gaining automatic layouts and multi-monitor workspaces.

Hoptoad has been renamed to Airbrake after a trademark dispute over frog- and toad-related names.

VirtualBox lacks a built-in VDI resize feature; enlarging the disk means cloning to a larger virtual drive and expanding the partition afterward.

dd copies can run silently until completion or failure; pkill -USR1 dd or status=progress reveals live transfer progress.

Windows 7 creates hidden Thumbs.db files in image folders, adding clutter to archives and shared files. Group Policy can stop thumbnail caching and file creation.

Inspect a gem's dependency requirements before installation to avoid surprises and see development-time packages such as hoe, rake-compiler, and rexical.