Aug. 18, 2026
What is Ploopy?
Ploopy is a company located in Canada that makes open-source mouse
with 3D printing material. They’re especially known for
creating trackball mouses with modern sensors.
Ploopy devices use QMK firmware by default, this
gives you a lot of flexibility to customize your mouse.
Ploopy Classic Trackball
Ploopy Classic is their most iconic model,
a modern, open-source 3D-printed imitation to
the Microsoft Trackball Explorer.
Aug. 17, 2026
Zotero is a free, easy-to-use tool to help collect, organize,
and cite research papers. This is widely used, and really helpful
for graduate students / researchers.
What’s nice is Zotero handles syncing of all the articles
you collected over the years as well as their attachments
(most likely PDFs of the corresponding article) on different machines.
The actual metadata of the articles that you saved are stored on the
zotero server for free, and to my knowledge, does NOT have a limit.
However, there is a limit on the attachment files stored on the Zotero server,
i.e. the actual PDFs for the articles. If you’re on the free-plan,
the upper limit quota is 300MB. For 2GB storage, you would need \$20 per year,
and 6GB for \$60 per year. See pricing here .
Jun. 29, 2026
Unified Modeling Language (UML) diagram is a standardized visual
diagram used to design and document the structure and behavior
of complex software systems.
Here is YouTube video that talks about the diagram usage.
There are many different types of diagram, and here I
keep a record of them for my personal usage.
UML Diagrams in Org-Mode
One of the ways to create a UML diagram in Org-Mode
is to use PlantUML , a simple language used for writing
UML diagrams.
Jun. 16, 2026
AMReX is a public software framework designed for building
massively parallel block-structured adaptive mesh refinement applications.
Here I keep track of the basic syntax or classes used in AMReX
for my personal notes.
Apr. 14, 2026
GDB , the GNU Project debugger, is a useful debugger for many
languages (C, C++, Fortran, etc). Here I keep a set of useful
commands for my records.
Using GDB
To use GDB, compile the program with debugging information.
For standard C++ program, add -g flag when compiling, i.e.
something like
1g++ -g -o myprogram myprogram.cpp
For AMReX related application codes like Castro, compile with
DEBUG=TRUE, i.e.
Jan. 17, 2026
Hugo is a static website generator written with GO, providing easily
capability to convert markdown files into a website. For those who use
emacs Org mode , one can use ox-hugo to convert Org files into markdown files
that will be compatible with Hugo. Hence the workflow is: