From Turbo Pascal to Delphi to C# to TypeScript, an interview with PL legend Anders Hejlsberg

Thanks much to Anders for the interview!
0:00 Video foreword
0:20 Introduction & current work
1:06 Getting into programming languages & Turbo Pascal
2:11 Lessons from early personal computing
3:26 Borland experience
4:36 Delphi
6:34 Graphical programming languages
7:54 Switch to Microsoft & background for .NET
9:56 C# in the context of Java
11:18 Classes vs structs & value objects
14:16 Getting into TypeScript
17:02 Surprising success
18:19 JS functional programming & TS feature set
19:55 Common Language Runtime & language vs platform
22:18 Future impact of machine learning on programming
24:02 Closing words

[@jaakkosalmenius8826]

Great person! Past 30 years I have basically only used languages written by Anders: Turbo Pascal, Delphi, C# and TypeScript

[@alexanderpoplawski577]

Same + Python.. I still have the WordStar key chords of Turbo Pascal / Turbo C burned into my muscle memory. Joe (Joe's own editor) is one of the first things I install on any new system.

[@ryan-heath]

Same here, but I have also used some basic, C/C++ and Java. Also a lot of Borland stuff. To bad they aren’t around anymore. JetBrains could be considered to have filled in the gap.

[@stephenhosking7384]

My programming career really started with Turbo Pascal, after I'd been programming for 10 years in different languages and editors. Turbo Pascal just brought out the joy of programming. Good to see so many comments here from people endorsing Turbo Pascal as significant moment in their development as programmers.

[@ddretnuh]

It’s been my core as well, if there’s one person’s shoulders I’ve stood on the most it’s Anders. Every other language/platform/etc I’ve worked in I end up comparing to how nice it his work was to use.

[@bjbell52]

No Paradox for Windows coding????

[@shimadabr]

It's pretty awesome this background "presentation" you do during the interview. Scrolling through wiki pages and other resources so we can even go on our own to deepen our understanding of the subjects being talked about.

[@stephenhosking7384]

Agree completely! It was a great addition to the interview.

[@BdR76]

Back in the 80s, Turbo Pascal was quite impressive, it was so fast both compiling and running the actual code, but also intuitive and very well documented. iirc some commercial msdos games were created using Turbo Pascal, like *Lemmings* and the official *Tetris* version.

[@AbhinavKulshreshtha]

Amazing interview. I love these old school stories.

[@contextfree]

And I also love when the stories come all the way into present times.

[@troyfrei2962]

I go back in the old turbo Pascal. As a Kid who had No money, I can remember paying less than $50.00 (from a ad out of Byte Mag?). I can remember the other Compilers costed Thousands in the 1980s. I can remember buying a video of David I on how to program in Delphi. I love Charles Calvert book on Delphi. I still LOVE Delphi. I was hopping Microsoft would buy Delphi one day. Thank you Mr Anders Hejlsberg for making a great product call Delphi.

[@cabc74]

I started with BASIC like all the kids that were introduced to home computers in the early 80's. But my first structured language with a PC was Turbo Pascal. That thing was fast!, had an IDE with a debugger and compiled programs faster than most languages today. Then, after doing briefly some VB (and hating it) Delphi wasborn. Delphi was awesome, it was object oriented Pascal with the good parts of VB and Turbo Pascal combined. Tragically, a year later all the hype of Java eclipsed it. I discovered C# i n 2002 after having struggled with Java. C# had the taste of Anders, and in many ways looked like Object Pascal with curly braces. I have done some typescript now, and its type system is great, but is javascript after all and is not my thing.

[@lp7489]

Thank you for sharing your journey in programming languages. I think I'll stay with Delphi.

[@MrPetzold123]

What a legend ! I've always liked his languages / products, all the way from Turbo Pascal.

[@phenanrithe]

C# is one of the best well-thought languages which continued to evolve in the right direction, congrats to everyone who worked on it!

[@matthewwood4756]

It was a well thought out language. Now, not so much.

[@phenanrithe]

@@matthewwood4756 I've stopped following after C#5 but until then, the evolution was very good and showed smart anticipation (unlike Java for instance). Has it badly turned after that?

[@matthewwood4756]

@@phenanrithe - it’s ok, but it’s starting to become something that it was never intended to be.

[@codediporpal]

It's hilarious this doesn't have more views. "Legend" is not an exaggeration.

[@zzord]

What a legend! I learned Turbo Pascal in high school, then started my career working on enterprise systems in Delphi, then switched to C#, (a little Java and Python in between), and today I'm a web dev using TypeScript.

[@MrWarMiki]

No way! I guessed Guido or Peyton Jones, but this is crazy :D

[@contextfree]

I do hope to interview both of them someday as well.

[@PKAnon]

I appreciate the tight editing on this. I feel it did not waste a moment of my time. His head is a bit choppy at times but that's a fair tradeoff since this kind of content is primarily audio.

[@tylovset]

A joy to listen to Mr. Hejlsberg.

[@benziegler5128]

Very interesting to learn about their "pre-Delphi" version that was like software IC. First time I heard about that.

[@stephenhosking7384]

When he mentioned it I recalled it. I don't recall it as a specifically Borland idea, but rather as a notion which was around at the time, ie. the idea of writing programs by connecting objects as in an IC. I may be wrong though, and it was specifically Borland. It did seem exciting at the time, and had a lot of "buzz". I laughed when he said "It was great for demos but didn't scale very well" (or, "scaled horribly", IIRC, LOL!). "Good for demos, but doesn't scale" would apply to A LOT of the ideas I've seen over the years, but especially I think in the late 80's/ early 90's.

[@fresky3843]

Great video, this is the first time I hear from Anders' natural language after using his programming languages for so many years😄

[@bobweiram6321]

Anders is GOAT! He's to programming what Seaborg is to nuclear physics. It's too bad Borland never released their Ada compiler.

[@DotnetareaBr]

I am very grateful to this person for all the things he created that are now part of my daily life.

[@edgeeffect]

I have massive nostalgia for Turbo C++ and Delphi and huge enthusiasm for TypeScript and speaking as someone who's overly critical of the vast majority of software, I think our friend Anders must be doing SOMETHING right. Thinking back to Delphi and looking at the bloated monstrosity that is Android Studio... there's just no comparison.

[@stephenhosking7384]

Missed opportunity! Near the end he talks about the promises of artificial intelligence and machine learning, including some futuristic ideas about AI and programming. He finishes with "keep on coding", and tells us that the languages and ideas which have been around for forty years have "a lot of staying power". Great! But, this was a golden opportunity to slip in that when our generation started programming forty years ago people were telling us we'd be "out of a job in ten years, because computers will be programming themselves". In 1986 I met a programmer who said that people had been telling him that since the 1960s. I wish he'd reminded us of that as the perfect close-off! Great interview! Thanks Anders for co-operating so generously, and thankyou to Context Free for the intelligent questions and the continuous background information.

[@claudiusraphael9423]

I loved the overall consistency (almost like the 60s form-follows-function meets least-aggressive-but-iconic-design - even within the rigid and confining limits of working at lowest resolution and in 40/80-character-mode in monochrome or 4 to 16 colors, keyboard-only most-dominantly, but still: ... spatially optimized for working with the equivalent to nowadays touchscreens, the lightpen or alternatively a space-mouse or plotting-glass with the nice side-effect of having one of the cleanest TUIs ever in use in production. The memorizable usage of shortcuts, on a separate layer the f-key navigation on systems supporting it, on yet another layer offering context-specific editing/navigation. All that mirrored in print with a phenomenally well written galaxy of books ... for one of the most beloved as well as belittled secret idols in the programming language universe - Pascal in all its derivatives and children .. Yeah, those times...

[@IleaCristian]

I also started with Turbo Pascal, hehe. Love the interview!

[@warungdoyong9821]

me too!

[@ranaictiu]

We developer community, so grateful to you for typescript...

[@contextfree]

As an aside, he wasn't the only originator of the TypeScript project, but my understanding is that he has been one of the core people since at least near the beginning.

[@Gordonfreems]

Amazing interview, I always admire when these legends make things seem so simple when they explain ideas

[@andersondamasceno1356]

Very good interview! the background presentation was a great idea.

[@ChrissKalogeropoulos]

He is one of the legends of software engineering

[@brujua7]

Great interview! Thanks a lot, hope you both are willing to do a round 2 in the future

[@flashchrome]

Very interesting. I just started my own journey in coding for C# and I think it is fairly easy to start but quite complex to learn.

[@dk_puck]

Hejlsberg is a rock star. I've been using his languages/tools since the early days of Borland. He would always attract quite a crowd when he was at Borland conferences.

[@ricardorojas7342]

Great interview!... I got nostalgic sice I started with pascal, then Delphi, currently on C# and next year will be facing typescript... Maybe, 🤔 I should tell my children to call him grandfather.

[@sivuyilemagutywa5286]

Love the way you show articles , it makes the interview more interesting 👏👏👏

[@josemonge4604]

Wow amazing! I've used Pascal, Typescript and C# and I really loved the developer experience. Really fan of Anders!

[@Tuxon86]

I love Turbo Pascal. My favorite language.

[@TomBauto]

Wow such refreshing interview, my memories all goes back when I learned those languages. Great interview by the way! Kudos!

[@dancehotelzumba3177]

This guy is a very humble genius. In my opinion, if you've initially worked on strongly typed languages, and you have some ability, you will grow into a much more efficient and error free programmer. Having worked with UCSD Pascal, then Turbo Pascal, then Delphi made me a much better C and C++ programmer than if I had learned in those languages. Typescript makes perfect sense in this regard. As I said, this guy is a genius. Not Zuck, not Bezos, not Gates. Gates was smart enough to hire him, which any reasonably intelligent person would do.

[@kamertonaudiophileplayer847]

I wrote a book about Turbo Pascal in 1990. It was about Windows programming using Turbo Pascal. Regarding Algol, it is interesting, I converted Algol programs to FORTRAN for a weather simulation. Regarding visual languages, I liked Modula. I think it is a very close to Rust, you simply couldn't write a wrong program.

[@d0m96]

Amazing interview!

[@lingdocs]

So thankful for the thoughts at 16:32, TypeScript is wonderful.

[@bigtymer4862]

Such a great interview!

[@helge000]

Great interview, thanks! "... more and more it is not about the language but rather about the platform" (20:15). This is something I seem to have observed rather inconspicuously over the last years.

[@thebasicmaterialsproject1892]

You know its veterans talk when borland is mentioned

[@aghileslounis]

easy like and subscribe, it's a very well done interview ! and i love the side notes/research you show when he is speaking, it makes it even more interesting, and more comprehensible, incredible video and what a time to be alive.

[@yutubl]

Thanks for all your work, which gave me better place to work for. I 've had the chance to learn Turbo Pascal on a university programming job, diplom thesis and use it several years for paid programming job (e.g. DIA/DAGO, DIAdem). I liked Delphi but I hadn't had the time for it beside small inhouse tool for my more Q&A related pre-DevOps job roles when C++/MFC, Windows Installer, C#/.NET, SQL, Java where the most used programming languages. And after using the advantages of static typed programming languages and their compile-time check possibilities for long time I miss type safety in all interpreter programming languages I learned (BASIC/VBS, JavaScript, Python) and the need for manually writing runtime checking code (per function entrance) is a little bit unmotivating. Thats why pure JS can't attract me that much.

[@artekgrupmakina1966]

Borland Turbo C++ 2.0 is my favorite

[@rumariomusic]

What a pleasure to hear this interview. I also started with Turbo Pascal. Then Borland Object Pascal, Delphi, C# and Typescript followed. Now I'm developing for VR and I'm back to C# again. But it needs a new VR language. I hope Anders is developing something

[@RikusLategan]

C# was inspired by the success of Visual Basic's rapid application development and the power and expressiveness of C++

[@sezgingul6166]

Great Interview

[@_Mikekkk]

I also started from Turbo Pascal from 90s, then Delphi (I love it), now learning C# because of Delphi is not supported in game development and C# looks very similar in OOP to Delphi.

[@ibgib]

yes, when I transitioned from Delphi to C# back at .net 2, it was like just going to the nextgen managed version of Delphi with so many awesome improvements.

[@colinmaharaj]

I love this guy, always will, he made Delphi and C++ Builder and the VCL framework, IDEs and languages I still use today. But jumping ship from Borland to MS then taking some of the tech to make .NET and C#, hmm, a bit disappointed, bu then again, Borland didn't survive. The Delphi and C++ Builder environs do survive in Embarcadero today however. Yep, I use C++ Builder XE4 today

[@cedgmail]

Great interview!

[@fernceborcena]

One of my idol in tech. I used all of his creation from pascal, delphi, c# and typescipt ❤ But, I love java and javascript 😂

[@jd31068]

That was super cool.

[@donnacasterr6223]

Anders is a Legend

[@chicoxiba]

amazing. I wish I had been presented with programming earlier. But cestlavie.

[@codecaine]

Absolute legend

[@RodHartzell]

Great interview. I cut my teeth on Turbo Pascal back in the 90s. Delphi was my introduction to pure OOP. The transition to C# was smooth after working with Delphi. And now nearly all front-end coding is Typescript. Anders wrote the platforms that gave me a career. Absolutely amazing that I followed exactly the path that Anders blazed throughout my lifetime. Thank you for the content.

[@naim3552]

That's owesome !

[@agou1980]

What a legend

[@quachhengtony7651]

Brilliant man

[@PhilippeElsass]

Legend.

[@eloyam9973]

What a masterclass 🤓

[@fburton8]

“boxes and lines going from everywhere to everywhere” National Instruments’ LabVIEW does that. It doesn’t scale well!

[@jacobusburger]

I wish I could subscribe to this channel more than once

[@denismijatovic1239]

Wonderful

[@HenaoGerman]

Excelent!

[@rdubb77]

Great interview!! HIs many years in the states has dampened his accent to the point of sounding like a Midwesterner. Which is interesting considering a lot of the midwestern immigrants came from Scandinavia.

[@victorarnault]

I Love that

[@landaucorl5390]

Dude, Anders does not need to introduce himself, lol 🙂. Awesome!!!

[@contextfree]

It's a way to hear him pronounce his own name (for an American English context) and express his preferred professional labels in the context of this discussion. I can say things about him, of course, but this lets us hear it from him directly.

[@landaucorl5390]

@@contextfree All right!

[@Duelweb]

How can one person be so talented and intelligent? You make my impostor syndrome 10x worse !! :)

[@rustybucket2248]

What a wonderful conversation. The creator of Java Jim Gosling, is a very smart interesting guy, don’t get me started on Pink flamingos. Sun Microsystems and Adobe systems were Frienemies Sun was making an impact in the computer engineering world, Adobe was at the center of curating the Transition from glass teletypes to Wyswyg Computing and printing systems. Both companies worked extensively with the C programming language. The desktop GUIs from Apple and Microsoft of the day were primitive and lacked functionality. Adobe PostScipt worked well as a bridge between those primitive environments and The sea of laser printers, Photo typesetters color monochrome grayscale and binary. For obscure reasons Jim Gosling set out to creat NEWS (Suns, clone of Adobe Display PostScript* Postscript with the extensions necessary for use as the GUI for a modern OS/computer[Display PostScript found in the NEXT computing environment]). NEWS and C Begate Java, which was a good thing. Jim Goslings horror at the lack of predictably of a low level language like C. Pointers, arrays, structures… at the end of the day were just memory addresses, no security, things like lint and prototypes tried to tame this beast, but failed. PostScript while a Turing complete language was interpreted, Yeah. But it was for all intents and purposes a write only language and the overwhelming majority of the code was transliterated from the GUI’s of the Systems that printed to Printers containing PostScript Firmware. Somewhere in this cloud of discontent Jim Came up with Java and spawned a new wave of creation. It was to be expected that having created a tool Java would get over used , misused and misunderstood. So here were are 30 years later and Java and JavaScript are alive and well. * so Are C and PostScript. I really resonate to the Minimalism of Making JavaScript a first class citizen of the Programming world. **Adobe Acrobat is the heir to NEWS and Display PostScript and People swear about problems with there PDF around the world. I recently was asked for an opinion about a kerfuffle in the legal world where an Attorney provided redacted documents to a court only to discover that in a paint order dependent rendering language which PostScript and Acrobat are. Drawing little black boxes in an editor over the content not meant to be disseminated did nothing to the underlying text and anyone with as midge of knowledge about files could deliver up the redacted text. A less lazy attorney would have at least printed out the document rescanned and saved the document as a new PDF or actually removed the redacted content from the original document and created a new document. We will never reach the promised land of The perfect Programming language, but it is nice to see that things are indeed getting better. Anders comment about the focus required to get something done with an 8 bit microprocessor takes me back more than 4 decades. The first Version of Adobe Illustrator, The first Desktop Application Adobe brought to market had to run on an Intel 286 on top MS Dos with segmented address space and the unholy constraints of the first 512K bytes of ram imposed by MS Dos. The product was developed under me and I had to promise every programmer that worked on it that we would never do that again. Every product after at Adobe was written for an unsegmented address space. Intel with the release of the I386 finally had a mode that the processor could run in that was unsegmented, though the carried the backwards compatible segmented addressing to keep things working in the Microsoft world. Oh dear I just meant to say thanks for the content. Best to all.

[@contextfree]

Thanks for the stories! I actually have one whole video some while back where I demo some PostScript because of the parentheses used for strings in it. And I never coded to segmented address spaces, and I haven't complained for missing out.

[@pyrocolada]

I still think I can crack a better visual / dataflow programming UI... once I get back to programming after a tour in other things.

[@myopainghan6399]

6:45 essentially the same problems low/No-code platforms have today. Man was ahead of the times

[@contextfree]

Yeah, VB, Delphi, and HyperCard were olden days versions of today's low code.

[@contextfree]

Well, I guess for your specific link, the software IC is more of the "no code" side of things.

[@freedom_aint_free]

I don't know if I call it a new addiction or a new love, but some call it "Functional Programming in Raku", I'm a sucker for operator and got pussy struck by the capacity of defining them on the fly, one of this days APL will really gonna get me.

[@lutfiikbalmajid]

I think my university too old, in 2018 i still using it. Now they migrated to c++

[@fr3ddyfr3sh]

PLEASE come back to C# and bring Erik Meijer with you. The current devs at MS really screw up things and add "features" to C#, nobody asked for. The lack of vision and the loss of connection to actual experienced c# users is staggering :-( When you ask them in a community meetup about csx, you just get plain stares. Or if you stumble upon the problem, that the Linq.Expression API/Compiler does not support nullables. 10 years after it was introduced 🤦‍♂ But they add super "top level statement program.cs" to make it more "beginner friendly", so to have one file in a project which has a completely different syntax to other files and cannot add arbitrary stuff, you can in regular program.cs. Just to name one thing. And kathleen anounces this stuff, as if it is the greates thing on earth. That really makes you smash your head against your keyboard, very hard.

[@lashlarue59]

What I want to know is I've only known 5 people from Denmark and 4 of them were named Anders. Is that name their equivalent of Joe or Bob or something?

[@lashlarue59]

@@pallekjrlaursen8388 Interesting! Thank you!

[@candy__.__candy]

No.

[@drbulltrader9107]

I have a question about .NET. Is it real the story around the fact .NET is what he called earlier Delphi Mobile?

[@contextfree]

.NET was developed at Microsoft and was started years after Anders left Borland. I'm not sure I understand the question. Do you have any links to details about your question?

[@michaelbasher]

He's one of the guys all software is progressed from. Top block eh..?

[@chaquirbemat6263]

i wish he was my grandfather

[@tobedecidedlater]

while(true){ Anders: blah blah blah... Other guy: That's awesome! }

[@bjbell52]

On your list of computer you left out .... 1979 Atari 800 1.79 MHz 16K . Come to think of it, you left out the Atari ST. In BOTH cases they were superior to the other computers that came out around the same time.

[@awunnenb]

Great, Please bring Pascal to Visual Studio :-)

[@PWRR]

Second..nth your motion/request! Nothing against Lazarus (or Delphi CE) but tooling does make a big difference in my attitude/level of enthusiasm.

[@awunnenb]

@@PWRR Pascal is an excellent language but Delphi 11 has such poor quaility and crashes daily. There are so many bugs over many versions that have never been fixed. I wish there was a Visual Studio or VSCode Integration for Pascal.

[@PWRR]

@@awunnenb Thank you for the warning. I was hoping that the Community Edition release of 11.# would include Linux support but now I am not so sure. Oh well, back to Lazarus/FPC for personal projects and Qt/PyQt/Avalonia/WPF because of the API's I need to target. At lease I don't have to do MFC anymore like I was doing when VS97 came out or some intermediate step/Java for Android applications today. I do miss the MSDN subscription packages that included Microsoft products but I would rather have Visual Studio be free with features I need or want than all the systems/applications I don't use or support. (I also blame them for getting me hooked on their ergonomic keyboards by giving me a beta version to test a few decades ago ;) )

[@skirmisherssouthport5056]

Oxygene programming language

[@mariobroselli3642]

Too bad you didnt ask him about new programming languages like go or Rust or which pure functional lang he enjoyed most . 😮

[@johanrg70]

The biggest mistake with Typescript is that the compiler itself is self hosted, meaning it's written in it's own language, so in the end it's a javascript application executed by Node. It's ineffective and slow wasting tons of programming time waiting for compiles to finish, it should have been written in a more suitable language like Rust or C++.

[@saltrocklamp199]

Is that not what Deno is?

[@johanrg70]

@@saltrocklamp199 Deno is written in Rust, and Node is written in C++ but both are using the v8 javascript engine internally which is written in C++. Both are just VM's for executing programs written in JS, which is single threaded and slower than a compiled language, this is fine for web apps and similar tools but not so for things like compilers (or transpilers in the case of Typescript). Compile times could easily be 100x faster in a better language. The sad part in all of this is that Anders Turbo Pascal compiler was blazingly fast compared to the competing compilers back in the day.

[@saltrocklamp199]

@@johanrg70 I see, I had thought Deno's Typescript compiler itself was written in Rust. Thanks for clarifying!

[@robertanderson5092]

OWL was better than MFC

[@mikegallagher4388]

Awesome, but why do that screen stuff? It should be the other way around. He should be the main thing.

[@mikegallagher4388]

I had to hide the screen.

[@stephenhosking7384]

Worked for me.

[@tmbarral664]

Anders, Frontend AND Backend nowadays, thanks to nodejs. ;)

[@UGPepe]

Typescript, like Java is necessary with mediocre programmers, not big projects. And I say that as a long-time Delphi developer. Kudos for mentioning how important closures are though.

[@chololennon]

Nonsense from nobody

[@UGPepe]

@@chololennon It's a known fact that Java was designed for mediocrity, even Gosling admitted it. Pike did the same with Go at Google and also admitted it, see a pattern here?