Any web browser with good support for SVG rendering, CSS, and JavaScript can be used as a client to a PML-TQ server (Firefox, Google Chrome, Opera browser, Safari, IE >=11).
A PML-TQ server hosted at ÚFAL can be accessed via LINDAT/Clarin web service (many of the treebanks are accessible freely, other treebanks require a login name and password - contact Matyáš Kopp to get information on how to obtain access to other treebanks).
A fully graphical client for the PML-TQ with client-side searching capability is part of the tree editor TrEd (a GPL-licensed software available separatelly) as an extension called pmltq. Several other extensions provide PML schemas and visualization stylesheets for various treebanks.
To install this extension, start TrEd, select Matyáš Kopp to get full access to the PML-TQ server hosted at ÚFAL).
and select 'pmltq'. When done, press Shift+F3 to start the search. Select for searching using a PML-TQ server, or 'Files (local)' for searching local files using client-side search engine built into the client (use empty username and password for publicly accessible treebanks or contactUnder development!