Dots in Gmail address by Ciro Santilli 37 Updated 2025-07-16
This allows you to create multiple non-anonymous accounts on any website that doesn't account for it, as this is not part of the email protocols in general.
Jitsi by Ciro Santilli 37 Updated 2025-07-16
As of 2020: end-to-end encryption optional and turned off as default, and marked as experimental...
Your profile picture, name and status are public by default as of 2022!!! OMG!!!
This means that all secret services in the world have alrady scraped this information for everyone that uses WhatsApp!!!
They just have to go incrementally through the list of all phone numbers... 001 0000 0000, 001 0000 0001, 001 0000 0002, etc. and then you can deduce who has which phone number.
OMG... it is analogous to the Facebook profile face dump.
For synthesized streams like sine we can do it e.g.
ffplay -autoexit -nodisp -f lavfi -i '
sine=frequency=500[a];
sine=frequency=1000[b];
[a][b]amerge, atrim=end=2
'
but it does not seem to accept multiple -i for some reason. So is there a way to open a file from some filter? E.g.:
ffplay -i tmp.wav -i tmp.mkv -filter_complex "[0:a]atrim=end=2[a];[1:v]trim=end=2[v]" -map '[a]' -map '[v]'
fails with:
Argument 'tmp.mkv' provided as input filename, but 'tmp.wav' was already specified.
ImageMagick by Ciro Santilli 37 Updated 2025-07-16
Crop 20 pixels from the bottom of the image:
convert image.png -gravity East -chop 20x0 result.png
Digits 0 to 9, white on black background:
for i in `seq 0 9`; do convert -size 512x512 xc:black -pointsize 500 -gravity center -fill white -draw "text 0,0 \"$i\"" $i.png; done
A more precise term for those in the know: open source software that also has a liberal license, for some definition of liberal.
Ciro Santilli defines liberal as: "can be commercialized without paying anything back" (but possibly subject to other restrictions).
He therefore does not consider Creative Commons licenses with NC to be FOSS.
For the newbs, the term open source software is good enough, since most open source software is also FOSS.
But when it's not, it's crucial to know.
This model can work well when there is a set of commonly used libraries that some developers often use together, but such that there isn't enough maintenance work for each one individually.
So what people do is to create a group that maintains all those projects, to try and get enough money to survive from the contributions done primarily for each one individually.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact