utilities to configure the MATE desktop
The MATE control center contains configuration applets for the MATE desktop, allowing to set accessibility configuration, desktop fonts, keyboard and mouse properties, sound setup, desktop theme and background, user interface properties, screen resolution, and other MATE parameters.
office productivity suite (metapackage)
LibreOffice is a full-featured office productivity suite that provides a near drop-in replacement for Microsoft(R) Office.
X terminal program with Thai languague support
xiterm+thai is an X terminal emulator program with Thai language support. It has built-in Thai keyboard input support. You could also use the X11 XKB extension to input Thai characters.
PuTTY terminal emulator
This is an X terminal emulator based on the popular Windows SSH client, PuTTY. It supports xterm escape sequences, plus some Linux console sequences for colour palette configuration and some DECterm sequences for title bar control, and with an appropriate font it supports the UTF-8 encoding of Unicode. It also has some nifty features like rectangular selection and NetHack keypad mode.
cross-platform multi-lingual music composition and notation, v2
MuseScore is an Open Source (GNU GPL) music notation software that runs on all platforms supported by Qt5 (GNU/Linux, MacOS X, Windows), and is available in over forty different languages. It features an easy to use WYSIWYG editor with audio score playback for results that look and sound beautiful, rivaling commercial offerings like Finale and Sibelius.
LilyPond sheet music text editor
Frescobaldi is a LilyPond sheet music editor. It aims to be powerful, yet lightweight and easy to use. Frescobaldi is Free Software, freely available under the GNU General Public License.