The Estonian Interlanguage Corpus of Tallinn University is the monolingual open resource (monitor corpus). The texts in the corpus have been mainly written by learners with the first language as Russian. It consists mainly of short essays, answers to questions and personal letters. The user can view the error annotated and syntactically tagged texts separately from the tags. Search can view examples of an error type of interest either in the context of the particular sentence or the whole text. The user can specify the search of error types and particular incorrect word forms by type of text. The user can link the search of language errors with the information about the learner’s level of competence in L2, his/her mother tongue, gender, education and occupation (student, employee, etc.). Corpus Statistics presents information about the same characteristics in the corpus and about the current size of the html-file, error annotated and syntactically tagged versions. The information about the learner's level of competence is based on the Common European Framework of Reference for Languages Council of Europe.