The presentation of this text with aids was done using open-source software called Ransom. The software can generate both screen-reading output like this and printer-friendly output.
Each page or section of the text has its own web page. The web page is split into panes, which are meant to be visualized spatially as if they were side by side. The idea is similar to the way the Loeb Classical Library books present Greek or Latin text on the left and English on the right facing page. However, the number of pages "side by side" is three rather than two. You can access the different panes by clicking on the triangles.
The main pane, which is the one you landed on, shows the foreign-langage text. In that pane, if you hover the mouse over a word, an interlinear gloss will pop up after a one-second delay. If you click on the word, a more detailed gloss pops up instead. Double clicking brings up a full-length dictionary entry from LSJ.
There is also a separate vocabulary pane in which lemmas are listed in alphabetical order. Only uncommon words are listed. If you like, you can study the vocabulary before reading the text.
The Greek text of the Anabasis is based on the edition by Marchant, 1904. The English translation is by Dakyns, 1901.
Text I've written, such as notes and glosses, is CC-BY-SA 4.0. Glosses taken verbatim from Cunliffe or White and Morgan are in the public domaion, as are the LSJ dictionary entries. Glosses taken verbatim from Wiktionary are CC-BY-SA 3.0. US law does not allow copyrighting of grammatical facts such as part-of-speech tagging and does not give any additional protection to databases beyond the normal protection of copyright.