As the only music encoding format, MEI natively supports not only various types of notation, but also fine-grained cross-references—both within a document and to other digital objects—as well as complex transcription-related and editorial markup. At the same time, there is a great need for suitable tools that are graphically oriented and enable easier and faster operation. In this project, "mei-friend" is extended with features that can assist in the generation and visual inspection of markup and annotations. Our goal is to reduce entry barriers in this area and thereby promote the dissemination of MEI for interactive and dynamic music resources.

mei-friend is an editor for MEI that aims to support and facilitate the 'last mile' of the music encoding process. This currently includes correcting encodings generated through conversion from other formats or using optical music recognition.

The tool is a cross-browser web application, thus requiring no additional software installation. It integrates the web-based code editor CodeMirror and the music engraving tool Verovio into a user-friendly graphical interface that enables interconnected navigation and editing of the MEI encoding, both as XML and through the graphical notation rendered by Verovio.

Above all, mei-friend offers a wealth of additional features to streamline workflows related to MEI, including schema-based code completion, GitHub integration, keyboard shortcuts, an easy-to-use interface to the MEI guidelines, and a directory of publicly licensed MEI encodings.

In this regard, mei-friend is intended to enable the creation of variants with additional readings through the cloning and simplified modification of selected passages and the user-friendly capture of sources. Additionally, the finding and management of markup should be made easier.

Furthermore, we aim for the simplified enrichment of MEI documents with score-related annotations, both through document-internal (inline) annotations using <annot> elements and in the form of standoff annotations following the Web Annotation Data Model recommended by the W3C. These standoff annotations are particularly suitable for scenarios where comments on a jointly used and published MEI resource are created by multiple users in different usage contexts. These standoff annotations can be stored online in a Personal Online Datastore (POD) of a Solid server to facilitate flexible and user-controlled annotation management in a low-threshold manner (cf. Weigl et al., "Read/Write Digital Libraries for Musicology," DLfM 2020, https://doi.org/10.1145/3424911.3425519).