As of GuiXT version 2011 Q1 1 you can store GuiXT scripts, images (gif, jpg) and InputScripts in the  "SAP MIME Repository", SAP transaction SE80. Compared with the older SAP Web Repository this has the following advantages:

• The MIME Repository supports the versioning of all files
• The files are stored in hierarchically organized folders
• The maintenance transaction SE80 offers greater comfort than SMW0 (Web Repository). It is used by SAP for Web Dynpro and BSP applications.
• There is a tool (ABAP program BSP_UPDATE_MIMEREPOS) for mass import and export from/to local folders.
• The file access can be done via http or WebDAV, in addition to the RFC (Remote Function Call) based access that is used by GuiXT.
• There is no need to "release" a function module for file access as is required in the Web Repository.

There are also some disadvantages:

• The first access for each file is slower, since 3 RFCs are needed instead of one. We suggest you make use of the VersionNumber statement so that the slower first access is irrelevant for productive usage.
• The user interface of the MIME repository is more complex

Using the notation SAPMR: in the same way as SAPWR: you can specify files and folders in the SAP Mime Repository in GuiXT scripts and GuiXT profile. Examples:

// GuiXT Profile
Directory1     SAPMR:SAP/BC/BSP/SAP/GUIXT

//Script
Image (toolbar)    SAPMR:SAP/BC/BSP/SAP/GUIXT/ICONS/help.gif

Screenshot transaction SE80, SAP MIME Repository:

Please see this tutorial for further details (by courtesy of the author, Freddie Botha).