$HOME (e. g. /opt/otrs/)
|
|  (all executables)
|--/bin/             (all system programs)
|   |--/otrs.PostMaster.pl      (email2db)
|   |--/otrs.PostMasterMail.pl  (email2db)
|   |--/cgi-bin/
|   |   |----- /index.pl        (Global Agent & Admin handle)
|   |   |----- /customer.pl     (Global Customer handle)
|   |   |----- /public.pl       (Global Public handle)
|   |   |----- /installer.pl    (Global Installer handle)
|   |   |----- /nph-genericinterface.pl (Global GenericInterface handle)
|   |--/fcgi-bin/               (If you're using FastCGI)
|
|  (all modules)
|--/Kernel/
|   |-----/Config.pm      (main configuration file)
|   |---- /Config/        (Configuration files)
|   |      |---- /Files/  (System generated, don't touch...)
|   |
|   |---- /Output/        (all output generating modules)
|   |      |---- /HTML/
|   |             |--- /Standard/*.dtl (all dtl files for Standard theme)
|   |
|   |--- /GenericInterface (GenericInterface framework)
|          |--- /Invoker/ (invoker backends)
|          |--- /Mapping/ (data mapping backends)
|          |--- /Operation/ (operation backends)
|          |--- /Transport/ (network transport backends)
|   |
|   |---- /Language/      (all translation files)
|   |
|   |---- /Modules/        (all action modules e. g. QueueView, Move, ...)
|   |      |----- /Admin*      (all modules for the admin interface)
|   |      |----- /Agent*      (all modules for the agent interface)
|   |      |----- /Customer*   (all modules for the customer interface)
|   |
|   |---- /System/         (back-end API modules, selection below)
|           |--- /Auth.pm        (authentication module)
|           |--- /AuthSession.pm (session authentication module)
|           |--- /DB.pm          (central DB interface)
|           |--- /DB/*.pm        (DB drivers)
|           |--- /DynamicField.pm (Interface to the DynamicField configuration)
|           |--- /DynamicField
|                 |--- /Backend.pm (Interface for using the dynamic fields)
|                 |--- /Backend/*.pm (DynamicField backend implementations)
|                 |--- /ObjectType/*.pm (DynamicField object type implementations)
|           |--- /Email.pm       (create and send e-mail)
|           |--- /EmailParser.pm (parsing e-mail)
|           |--- /GenericInterface/*.pm (all DB related GenericInterface modules)
|           |--- /Group.pm       (group module)
|           |--- /Log.pm         (log module)
|           |--- /Queue.pm       (information about queues. e. g. responses, ...)
|           |--- /Scheduler      (Scheduler files)
|                 |--- /TaskHandler/ (task handler backends for the Scheduler)
|           |--- /Ticket.pm      (ticket and article functions)
|           |--- /User.pm        (user module)
|           |--- /Request.pm    (HTTP/CGI abstraction module)
|
|  (data stuff)
|--/var/
|   |--/article/               (all incoming e-mails, plain 1/1 and all attachments ...
|   |                            ... separately (different files), if you want to store on disk)
|   |--/cron/                  (all cron jobs for escalations and such)
|   |
|   |--/fonts/                 (true type fonts for PDF generation)
|   |
|   |--/httpd/                 (all static files served by HTTP)
|   |   |--- /htdocs/
|   |         |--- /js/        (javascript files for OTRS)
|   |               |--- /js-cache/        (auto-generated minified JS files)
|   |               |--- /thirdparty/      (contains jQuery, CKEditor and other external JS libraries)
|   |         |--- /skins/     (CSS and images for front end)
|   |               |--- /Agent/        (Agent skins)
|   |                     |--- /default/ (default skin)
|   |                           |--- /css/ (stylesheets)
|   |                           |--- /css-cache/ (auto-generated minified CSS files)
|   |                           |--- /img/ (images)
|   |                     |--- /slim/    (additional skin)
|   |                           |--- /.../ (files)
|   |                     |--- /ivory/   (additional skin)
|   |                           |--- /.../ (files)
|   |               |--- /Customer/     (Customer skins)
|   |                     |--- /default/ (default skin)
|   |                           |--- /.../ (files)
|   |                     |--- /ivory/
|   |                           |--- /.../ (files)
|   |
|   |--/log/                   (log files)
|   |   |--/TicketCounter.log  (ticket counter)
|   |
|   |--/sessions/              (session info)
|   |
|   |--/spool/                 (spool files)
|   |
|   |--/stats/                 (statistics)
|   |
|   |--/tmp/                   (temporary files, such as cache)
|
|  (tools stuff)
|--/scripts/
|   |----  /database/
|           |--- /otrs-schema.(mysql|postgresql|*).sql (create database script)
|           |--- /otrs-initial_insert.(mysql|postgresql|*).sql (all initial sql data - e. g.
|           |                                                   root user, queues, ...)
|           |--- /otrs-schema-post.(mysql|postgresql|*).sql (create foreign keys script)
|