The package ocgtools is designed to insert OGC (Optional Group Content, known as layers) into PDF presentations. From the user's point of view, the package allows to insert in an comfortable way any TeX material into separate layers in PDF document and also insert links which toggle theselayers on and off. Parts of the PDF document like formatted text, tables, math formulas or graphics can be turned to visible or inivisible state by clicking active links or buttons. Similar packages are cooltooltips, pdfcomment, AcroTeX and fancytooltips. See the ocgtools package documentation for differences between ocgtools and the other packages. The package is distributed with examples build from one source using several presentation packages (beamer, web, pdfscreen). All necessary files are on CATN and Texlive 2009. Supported by the grant 131/2010 of Higher Education Development Fund (www.frvs.cz).