Many languages are in serious danger of being lost and as a result, there has been a significant increase in language documentation projects, and also in attempts to preserve language documentation via the use of digital technologies. We are developing a distributed digital library for endangered languages which will contain various data of endangered languages in the forms of text, image, video, audio and include advanced tools for intelligent cataloging, indexing, searching and browsing information on languages and language analysis. As part of this project, we developed ImageSpace, an ontology creation and annotation tool that currently supports both texts and images. In this paper, we share our experience of annotating linguistic data with ImageSpace.