The Czech Academic Corpus version 1.01 is a corpus with a manual annotation of morphology of the Czech language consisting of approximately 600,000 words in continuous texts. The process and the size of the Czech Academic Corpus (CAC) project differs from every traditional project. The primary goal of this project was to create a computerized corpus that would contain manual annotation of morphology and syntax of Czech. This manual annotation of morphology and syntax was initially developed more than twenty years ago (1971-1985) at the Institute of the Czech Language of the Czech Academy of Science as a basis for constructing a frequency dictionary of Czech at that time. Having mentioned the years when the history of CAC has started we cannot miss the fact that there were available two computerized annotated corpora in the 1960s Brown Corpus of American English and LOB Corpus of British English. Both corpora became well known to the corpus linguists whereas CAC (although containing richer annotation schemes) has remained hidden mainly because of the political regime of the 1980s in the Czech Republic. Fortunately for Czech computational linguistics, CAC was (and still is, obviously) of significant importance because the very first experiments on the corpus-based processing of Czech could be performed thanks to CAC. Independent from CAC, the project of the Prague Dependency Treebank (PDT) was launched in 1996. The complexity of the PDT three-layer annotations (morphological, syntactic-analytical, tectogrammatical) is reflected in the volume of the annotated data 2 million words are annotated only morphologically, 1,5 million words have also an analytic annotation and from them 800,000 words is provided with tectogrammatical annotation. The second version of PDT has been released in summer 2006 (Hajic et al., 2006), (PDT 2.0, 2006). The experience acquired from annotating such a huge volume of data is so exceptional and illuminating that it has become one of the main motivations for further work within CAC the idea of converting the internal format and annotation schemes of CAC in a way that they would be compatible within PDT was proposed. This conversion will facilitate the possibility of integrating CAC annotations directly into PDT. The currently released first version of CAC (CAC 1.0, 2006) is a result of conversion of the internal format and morphological annotations. The guide to the CAC 1.0 (Hladka et al., 2006) is a road map to the CD-ROM which offers: