diff --git a/guides/source/action_controller_overview.textile b/guides/source/action_controller_overview.md
similarity index 100%
rename from guides/source/action_controller_overview.textile
rename to guides/source/action_controller_overview.md
diff --git a/guides/source/action_mailer_basics.textile b/guides/source/action_mailer_basics.md
similarity index 100%
rename from guides/source/action_mailer_basics.textile
rename to guides/source/action_mailer_basics.md
diff --git a/guides/source/action_view_overview.textile b/guides/source/action_view_overview.md
similarity index 100%
rename from guides/source/action_view_overview.textile
rename to guides/source/action_view_overview.md
diff --git a/guides/source/active_model_basics.textile b/guides/source/active_model_basics.md
similarity index 100%
rename from guides/source/active_model_basics.textile
rename to guides/source/active_model_basics.md
diff --git a/guides/source/active_record_basics.textile b/guides/source/active_record_basics.md
similarity index 100%
rename from guides/source/active_record_basics.textile
rename to guides/source/active_record_basics.md
diff --git a/guides/source/active_record_querying.textile b/guides/source/active_record_querying.md
similarity index 100%
rename from guides/source/active_record_querying.textile
rename to guides/source/active_record_querying.md
diff --git a/guides/source/active_record_validations_callbacks.textile b/guides/source/active_record_validations_callbacks.md
similarity index 100%
rename from guides/source/active_record_validations_callbacks.textile
rename to guides/source/active_record_validations_callbacks.md
diff --git a/guides/source/active_support_core_extensions.textile b/guides/source/active_support_core_extensions.md
similarity index 100%
rename from guides/source/active_support_core_extensions.textile
rename to guides/source/active_support_core_extensions.md
diff --git a/guides/source/active_support_instrumentation.textile b/guides/source/active_support_instrumentation.md
similarity index 100%
rename from guides/source/active_support_instrumentation.textile
rename to guides/source/active_support_instrumentation.md
diff --git a/guides/source/ajax_on_rails.textile b/guides/source/ajax_on_rails.md
similarity index 100%
rename from guides/source/ajax_on_rails.textile
rename to guides/source/ajax_on_rails.md
diff --git a/guides/source/api_documentation_guidelines.textile b/guides/source/api_documentation_guidelines.md
similarity index 100%
rename from guides/source/api_documentation_guidelines.textile
rename to guides/source/api_documentation_guidelines.md
diff --git a/guides/source/asset_pipeline.textile b/guides/source/asset_pipeline.md
similarity index 100%
rename from guides/source/asset_pipeline.textile
rename to guides/source/asset_pipeline.md
diff --git a/guides/source/association_basics.textile b/guides/source/association_basics.md
similarity index 100%
rename from guides/source/association_basics.textile
rename to guides/source/association_basics.md
diff --git a/guides/source/caching_with_rails.textile b/guides/source/caching_with_rails.md
similarity index 100%
rename from guides/source/caching_with_rails.textile
rename to guides/source/caching_with_rails.md
diff --git a/guides/source/command_line.textile b/guides/source/command_line.md
similarity index 100%
rename from guides/source/command_line.textile
rename to guides/source/command_line.md
diff --git a/guides/source/configuring.textile b/guides/source/configuring.md
similarity index 100%
rename from guides/source/configuring.textile
rename to guides/source/configuring.md
diff --git a/guides/source/contributing_to_ruby_on_rails.textile b/guides/source/contributing_to_ruby_on_rails.md
similarity index 100%
rename from guides/source/contributing_to_ruby_on_rails.textile
rename to guides/source/contributing_to_ruby_on_rails.md
diff --git a/guides/source/debugging_rails_applications.textile b/guides/source/debugging_rails_applications.md
similarity index 100%
rename from guides/source/debugging_rails_applications.textile
rename to guides/source/debugging_rails_applications.md
diff --git a/guides/source/engines.textile b/guides/source/engines.md
similarity index 100%
rename from guides/source/engines.textile
rename to guides/source/engines.md
diff --git a/guides/source/form_helpers.textile b/guides/source/form_helpers.md
similarity index 100%
rename from guides/source/form_helpers.textile
rename to guides/source/form_helpers.md
diff --git a/guides/source/generators.textile b/guides/source/generators.md
similarity index 100%
rename from guides/source/generators.textile
rename to guides/source/generators.md
diff --git a/guides/source/getting_started.textile b/guides/source/getting_started.md
similarity index 100%
rename from guides/source/getting_started.textile
rename to guides/source/getting_started.md
diff --git a/guides/source/i18n.textile b/guides/source/i18n.md
similarity index 100%
rename from guides/source/i18n.textile
rename to guides/source/i18n.md
diff --git a/guides/source/initialization.textile b/guides/source/initialization.md
similarity index 100%
rename from guides/source/initialization.textile
rename to guides/source/initialization.md
diff --git a/guides/source/layouts_and_rendering.textile b/guides/source/layouts_and_rendering.md
similarity index 100%
rename from guides/source/layouts_and_rendering.textile
rename to guides/source/layouts_and_rendering.md
diff --git a/guides/source/migrations.textile b/guides/source/migrations.md
similarity index 100%
rename from guides/source/migrations.textile
rename to guides/source/migrations.md
diff --git a/guides/source/nested_model_forms.textile b/guides/source/nested_model_forms.md
similarity index 100%
rename from guides/source/nested_model_forms.textile
rename to guides/source/nested_model_forms.md
diff --git a/guides/source/performance_testing.textile b/guides/source/performance_testing.md
similarity index 100%
rename from guides/source/performance_testing.textile
rename to guides/source/performance_testing.md
diff --git a/guides/source/plugins.textile b/guides/source/plugins.md
similarity index 100%
rename from guides/source/plugins.textile
rename to guides/source/plugins.md
diff --git a/guides/source/rails_application_templates.textile b/guides/source/rails_application_templates.md
similarity index 100%
rename from guides/source/rails_application_templates.textile
rename to guides/source/rails_application_templates.md
diff --git a/guides/source/rails_on_rack.textile b/guides/source/rails_on_rack.md
similarity index 100%
rename from guides/source/rails_on_rack.textile
rename to guides/source/rails_on_rack.md
diff --git a/guides/source/routing.textile b/guides/source/routing.md
similarity index 100%
rename from guides/source/routing.textile
rename to guides/source/routing.md
diff --git a/guides/source/ruby_on_rails_guides_guidelines.textile b/guides/source/ruby_on_rails_guides_guidelines.md
similarity index 100%
rename from guides/source/ruby_on_rails_guides_guidelines.textile
rename to guides/source/ruby_on_rails_guides_guidelines.md
diff --git a/guides/source/security.textile b/guides/source/security.md
similarity index 100%
rename from guides/source/security.textile
rename to guides/source/security.md
diff --git a/guides/source/testing.textile b/guides/source/testing.md
similarity index 100%
rename from guides/source/testing.textile
rename to guides/source/testing.md
diff --git a/guides/source/upgrading_ruby_on_rails.textile b/guides/source/upgrading_ruby_on_rails.md
similarity index 100%
rename from guides/source/upgrading_ruby_on_rails.textile
rename to guides/source/upgrading_ruby_on_rails.md