Following the recent upsets with both Twitter and Reddit, how have people here been exporting/archiving their bookmarked/favorited/liked/etc threads, posts, and the content within (images, links, etc) for later reference?

It hit me not too long ago that there’s a lot of good stuff I’ve bookmarked over the years on both and it’d be unfortunate for viewing it to be locked behind keeping accounts active. Additionally, more and more of it’s disappearing over time not just due to link rot (which seems to have been accelerating dramatically in the past decade), but also as a result of users deleting their posts on the way out.

I’m particularly interested in solutions that saves content locally, because exporting these things to e.g. a cloud read it later service or bookmark manager really just shifts the problem around instead of solving it, but beggars can’t be choosers and all that.

Hello Tildes,

I am currently taking DSA in college and struggling a lot with the math and algorithms. Recently had to solve Karatsuba questions and I don't even know what I wrote down on the paper. I have been trying to look for videos on this and only really came away with a vague understanding.

What I've noticed is that I struggle with solving the math part of the questions.

For example: "Describe a divide and conquer algorithm to compute the square
of an n-digit integer in O(n log3 5) time, by reducing to the squaring of five [n/3]-digit
integers"

I have zero clue how I am supposed to understand the latter half of the question. It makes no sense to me beyond I am supposed to be multiplying squared numbers. How do I even begin to turn this into an algorithm? What is the solution even supposed to look like?

Needless to say, I've struggled with math my entire life and I've been trying for years to be decent with it, and I have nothing to show for it.

So, do you have any recommendations that could simplify the math needed for DSA? Videos are preferred but I will textbook recommendations as well.

Thank you, and have a good day!

The history of the web is littered with with many a dead image/video hosting service. Echos of their existence plague older forums in the form of broken links and images. It seems like they all follow the same path, starting up as the new "simple" service that just hosts images, no fuss. But then as interest grows, so do costs, and the service owners have to scramble to monetize. Generally this is done by stuffing the place full of ads until everyone leaves. Alternatively the owners are stubborn and stick to their guns, until they inevitably have to shut down due to drowning in costs. When they do shut down, millions of assets are lost and the graveyard of broken images across the web grows some more.

https://gfycat.com/ is the latest notable victim of this.

With all the recent social media turmoil, there as been lots of exploration of alternative sites, and all of them have to overcome the problem of hosting media in one way or another.

Tildes obviously does this by avoiding it entirely which, while a very effective solution, is just handballing the problem elsewhere. Users will still want to post images and videos but they will just have to find alternative hosts. Over time those hosts will die and Tildes posts will be filled with dead links.

Mastodon has similar problems,the biggest cost of hosting a mastodon instance is the storage and bandwidth required to facilitate media posts. And there's a real danger of an instance incurring high costs if a particular post becomes popular and is hotlinked on a big centralised social media site.

It seems like a really tricky problem to solve, something peer-to-peer could sort of solve the costs created by traffic peaks but has problems when there is many small files viewed by few individuals each.

Are there any other solutions out there? Web3, IPFS? Or is it just not that much of a problem, do we accept that media on the web is ephemeral and will be lost after a while?

TLDR:

I need a website that let's signed in users vote on each others photos, and stores that data on who voted for what in a database.

Background

I run a facebook group of about 2,000 members. This group is designed for analog (any non-digital format) photographers to swap high quality artistic prints with each oter. The community was essentially dead and the admin wanted to throw in the towel so I took over. We've made progress, the group growth jumped by over 500% in the first month after I took over.

Right now trading prints doesn't work well. People make a post using the facebook selling format, and those who are interested comment with the image they'd like to trade for. The problem is that the posts get limited visibility due to facebook's algorithms, and stale posts hang around. All of this reduces over all activity, and the majority of posts don't end up in a trade.

My solution is to do a trade event with everyone participating at the same time. Since facebook doesn't lend itself to this I'd like to whip up a quick site for the event. My time is so limited these days I really don't have the capacity to build something from scratch, and the group certainly doesn't have any other developers to help out with it (it skews heavily on the older side).

I'd like to find an open source project that lets users sign in (sign in using facebook would be a bonus) and upload/vote on images. After the voting closes, I'll write code to pair everyone up in a way that optimizes for everyone getting to make a trade. If Alice votes for Bob's image, and Bob votes for Alice's image, they would get paired up to make the swap.

I feel okay writing the code to map out swaps, but I'm pretty terrible at web design and especially at front end design. I've looked across github, but I wanted to reach out and see if anyone could recommend something that I might of missed.

I don't expect to have 2,000 members participate, I think it may be as few as under 100, so hopefully I won't need to worry about scale.

Thanks in advance for the help!

I have been writing a paper on the history of a type of online social space called public access Unix systems, and I'm posting a Tildes-tailored summary here in case anyone is interested. If you enjoy this and want to read more (like 10+ pages more) look at the bottom of this post for a link to the main paper-- it has citations, quotes, and everything, just like a real pseudo-academic paper!

I wrote this because a summary didn't exist and writing it was a way for me to learn about the history. It was not written with the intent of commercial publication, but I'd still love to share it around and get more feedback, especially if that would help me further develop the description of this history and these ideas. If you have any thoughts about this, please let me know.

What are Public Access Unix Systems?

When the general public thinks of the Unix operating system (if it does at all), it probably isn't thinking about a social club. But at its core, Unix has a social architecture, and there is a surprisingly large subculture of people who have been using Unix and Unix-like operating systems this way for a long time.

Public access Unix systems are multi-user systems that provide shell accounts to the general public for free or low cost. The shell account typically provides users with an email account, text-based web browsers, file storage space, a directory for hosting website files, software compilers and interpreters, and a number of tools for socializing with others on the system. The social tools include the well-known IRC (Internet Relay Chat), various flavors of bulletin-board systems, often a number of homegrown communication tools, and a set of classic Unix commands for finding information about or communicating with other system users.

But more than just mere shell providers, public access Unix systems have always had a focus on the social community of users that develops within them. Some current systems have been online for several decades and many users have developed long-standing friendships and even business partnerships through them. i.e. they're a lot of fun and useful too.

Of interest to Tildes members is that public access Unix systems have for the most part been non-commercial. Some take donations or charge membership fees for certain tiers of access (some in the U.S. are registered 501(c)(3) or 501(c)(7) non profits). They almost invariably do not take advertising revenue, do not sell user profile data, and the user bases within them maintain a fairly strong culture of concern about the state of the modern commercial Internet.

This concept of a non-commercial, socially aware, creative space is what really got me interested in the history of these systems. Further, the fact that you have this socially aware, technically competent group of people using and maintaining a medium of electronic communication seems particularly important in the midst of the current corporate takeover of Internet media.

History

Public access Unix systems have been around since the early 1980's, back when most of the general public did not have home computers, before there was a commercial Internet, and long before the World Wide Web. Users of the early systems dialed in directly to a Unix server using a modem, and simultaneous user connections were limited by the number of modems a system had. If a system had just one modem, you might have to dial in repeatedly until the previous user logged off and the line opened up.

These early systems were mostly used for bulletin-board functionality, in which users interacted with each other by leaving and reading text messages on the system. During this same time in the early 80's, other dial-in systems existed that were more definitively labeled "BBSes". Their history has been thoroughly documented in film (The BBS Documentary by Jason Scott) and in a great Wikipedia article. These other systems (pure BBSes) did not run the Unix OS and many advanced computer hobbyists turned up their noses at what they saw as toyish alternatives to the Unix OS.

Access to early dial-in public access Unix systems was mostly constrained by prohibitively expensive long-distance phone charges, so the user bases drew from local calling areas. The consequence was that people might meet each other online, but there was a chance they could end up meeting in person too because they might literally be living just down the street from each other.

The first two public access Unix systems were M-Net (in Ann Arbor, MI) and Chinet (in Chicago, IL), both started in 1982. By the late 1980's, there were more than 70 such systems online. And at their peak in the early 1990's, a list of public access Unix systems shared on Usenet contained well over 100 entries.

Throughout the 1980's, modem speeds and computer power increased rapidly, and so did the functionality and number of users on these systems. But the 1990's were a time of major change for public access Unix systems. In 1991, the Linux operating system was first released, ushering in a new era of hobbyist system admins and programmers. And new commercial services like AOL, Prodigy and CompuServe brought hordes of new people online.

The massive influx of new people online had two big impacts on public access Unix systems. For one, as access became easier, online time became less precious and people were less careful and thoughtful about their behavior online. Many still describe their disappointment with this period and their memory of the time when thoughtful and interesting interactions on public access Unix systems degraded to LOLCAT memes. In Usenet (newsgroups) history, the analogous impact is what is referred to as "The Eternal September".

The second impact of this period was from the massive increase of computer hobbyists online. Within this group were a small but high-impact number of "script kiddies" and blackhat hackers that abused the openness of public access Unix systems for their own purposes (e.g. sending spam, hacking other systems, sharing illegal files). Because of this type of behavior, many public access Unix systems had to lock down previously open services, including outbound network connections and even email in some cases.

For the next decade or so, public access Unix systems continued to evolve with the times, but usership leveled off or even decreased. The few systems that remained seemed to gain a particular sense of self-awareness in response to the growing cacophony and questionable ethics of the commercial World Wide Web. This awareness and sense of identity continues to this day, and I'll describe it more below because I think it is really important, and I expect Tildes members agree.

2014 and Beyond

In 2014, Paul Ford casually initiated a new phase in the history of public access Unix systems. He registered a URL for tilde.club (http://tilde.club) and pointed it at a relatively unmodified Linux server. (Note: if there is any relation between tilde.club and Tildes.net, I don't know about it.) After announcing via Twitter that anyone could sign up for a free shell account, Ford rapidly saw hundreds of new users sign up. Somehow this idea had caught the interest of a new generation. The system became really active and the model of offering a relatively unmodified *NIX server for public use (a public access Unix system under a different name) became a "thing".

Tilde.club inspired many others to open similar systems, including tilde.town, tilde.team* and others which are still active and growing today. The ecosystem of these systems is sometimes called the tilde.verse. These systems maintain the same weariness of the commercial WWW that other public access Unix systems do, but they also have a much more active focus on building a "radically inclusive" and highly interactive community revolving around learning and teaching Unix and programming. These communities are much, much smaller than even small commercial social networks, but that is probably part of their charm. (* full disclosure, I wield sudo on tilde.team.)

These tilde.boxes aren't the only public access Unix systems online today though. Many others have started up in the past several years, and others have carried on from older roots. One of the most well known systems alive today is the Super Dimension Fortress (SDF.org) that has been going strong for over three decades. Grex.org and Nyx.net have been online for nearly as long too. And Devio.us is another great system, with a community focused around the Unix OS, particularly OpenBSD. Not all these systems label themselves as "public access Unix systems", but they all share the same fundamental spirit.

One system that I find particularly interesting is Hashbang (aka #!, https://hashbang.sh). Hashbang is a Debian server run and used by a number of IT professionals who are dedicated to the concept of an online hackerspace and training ground for sysadmins. The system itself is undergoing continual development, managed in a git repository, and users can interact to learn everything from basic shell scripting to devops automation tooling.

Why is Hashbang so cool? Because it is community oriented system in which users can learn proficiency in the infrastructural skills that can keep electronic communications in the hands of the people. When you use Facebook, you don't learn how to run a Facebook. But when you use Hashbang (and by "use", I mean pour blood, sweat and tears into learning through doing), you can learn the skills to run your own system.

Societal role

If you've read other things I've written, or if you've interacted with me online, then you know that I feel corporate control of media is a huge, huge concern (like Herman and Chomsky type concern). It's one of the reasons I think Tildes.net is so special. Public access Unix systems are valuable here too because they are focused on person-to-person connections that are not mediated by a corporate-owned infrastructure, and they are typically non-profit organizations that do not track and sell user data.

You're no doubt aware of the recent repeal of Net Neutrality laws in the U.S., and you're probably aware of what The Economist magazine calls "BAADD" tech companies (big, anti-competitive, addictive and destructive to democracy). One of the most important concerns underlying all of this is that corporations are increasingly in control of our news media and other means of communication. They have little incentive to provide us with important and unbiased information. Instead, they have incentive to dazzle us with vapid clickbait so that we can be corralled past advertisements.

Public access Unix systems are not the solution to this problem, but they can be part of a broader solution. These systems are populated by independently minded users who are skeptical of the corporate mainstream media, and importantly, they teach about and control the medium of communication and social interaction itself.

Unix as a social medium

So what is it that makes public access Unix systems different? This seems like a particularly interesting question relative to Tildes (so interesting that I even wrote another Tildes post about it). My argument is partly that Unix itself is a social and communication medium and that the structure of this medium filters out low-effort participation. In addition to this, public access Unix systems tend to have user bases with a common sense of purpose (Unix and programming), so users can expect to find others with shared interests.

In contrast to modern social media sites like Facebook or Twitter, you have to put in some effort to use Unix. You have to learn to connect, typically over ssh; you have to learn to navigate a command line shell; and you have to learn the commands and options to run various utilities. And to really use Unix, you have to learn a bit of programming. It's not incredibly hard in the end, but it takes significantly more effort than registering for a Facebook or Twitter account and permitting them to scan your email address book. Once you get over the learning curve, it is powerful and fun.

This effortful medium does two things. For one, it weeds out people who aren't willing to put in effort. And for two, it provides learned users with a diverse palette of tools and utilities for building and sharing creative output.

Public access Unix systems are all about active creation of content to be enjoyed and shared with others, and not about passive media consumption. They are about the community that develops around this purpose and not around the profit that can be squeezed out of users' attention.

Future of public access Unix systems

Public access Unix systems have been around for nearly four decades now. They have seen ups and downs in popularity, and they have been humming along in the background as computing has gone from the ARPANET to the spectacle of the commercial World Wide Web. Early public access Unix systems were largely about the novelty of socializing with other hobbyists through a computer, and that interest has evolved into the learning, doing and teaching model of an online hackerspace today.

These systems are not huge, they are not coasting on advertising revenue, and they get by purely on the contributions, volunteer effort, and enthusiastic participation of their users. But as a contrast to commercial social network sites, they are an example of what online socializing can be when individuals put effort, thought, and compassion into their interactions with others. And just as importantly, they pass on the very skills that can independently maintain this social and communication medium for future generations of users.

--

As promised in the intro, if you're interested in reading a much more in-depth version of this article, here's the longer copy:
https://cmccabe.sdf.org/files/pubax_unix_v01.pdf