On Aug. 6, 1991, the World Wide Web became accessible to the public. To celebrate the 25th birthday of this world-changing event, we asked founders of some of the first dot-com companies and inventors of some of the most fundamental internet technologies to look back on their careers and share their contributions.

We also requested that they reflect upon the web collectively and remark upon its high and low points throughout the past 25 years. While the advent of the web and its underlying technologies have resulted in the most concentrated period of innovation in history, many internet pioneers believe that a lack of awareness of what could be possible online stunted the web’s growth in its early years. They also identify trade offs and contradictions in some of the web’s most prominent features, such as the ability to unite humanity and provide a platform for further divisions.

Click through to read remarks from some of the web’s earliest entrepreneurs and learn what has surprised them about the trajectory the web has taken.

Biz Stone

Bloomberg | Getty Images

Co-founder of Jelly Industries, Medium and Twitter

What are you most proud of, with regards to your contributions to the internet?

“The idea that got me into the business of being an internet entrepreneur was that of giving voice to the voiceless. It started with blogging in 1999 -- the idea that people could make web pages without knowing how to code. At Google, I worked on the Blogger team, then founded Twitter and later Medium. I’m most proud of giving voice to the voiceless and elevating the freedom of speech to a basic human right.”

What do you wish you could go back and change?

“With Twitter, specifically regarding our early technical approach, if there was a right way of doing something and a wrong way of doing it, we chose the wrong way an absurdly disproportionate amount of the time. It would be easy to say I wish I could go back and change Twitter’s early technical approach to one that was designed to scale from the beginning. However, because of the way everything worked out, I wouldn’t want to go back and change anything because it worked out positively beyond my wildest dreams.”

What do you think is one of the best moments in internet history?

“Blogging really was a revolution -- it was also a revelation and an enlightenment. Blogging paved the way for Twitter, and Twitter paved the way to a new standard for freedom of speech, transparency and the speed of information flow.”

What do you think is one of the low points in internet history?

“It seems there cannot be good without bad. One of the low points in internet history is the emergence and existence of cyberwarfare -- something that the world needs to take seriously right now as a legitimately dangerous threat to human lives and society. We need to bring more light into the darkness. I believe the fundamental goodness of humanity will prevail. I believe the reason we are so connected is so that we can help each other -- this is the motivation behind my newest pursuit, askjelly.com, a new breed of search engine that prompts people to help one another in this incredibly hyperconnected age.”

Vinton Cerf

Alex Wong | Getty Images

Considered one of the “fathers of the internet” for co-designing the TCP/IP protocols and the architecture of the internet; recipient of the U.S. National Medal of Technology, ACM Alan M. Turing Award and the President Medal of Freedom; former founding president of the Internet Society; vice president and Chief Internet Evangelist at Google since 2005

What are you most proud of, with regards to your contributions to the internet?

“I think the architecture and core protocols have been remarkably robust over decades and that the system has allowed so many people to contribute their ideas (and new protocols) and new transmission/switching technology to the internet. It has been able to absorb and facilitate innovation in many dimensions. The WWW is a good (but not the only) example. Streaming audio and video, mobile apps are among the others.

“Moreover, the institutions around the internet have also proven to be flexible and open: the Internet Architecture Board, the Internet Engineering and Research Task Forces, the Internet Society, the Internet Corporation for Assigned Names and Numbers, the Regional Internet Registries (ARIN, RIPE-NCC, APNIC, LACNIC and AFRINIC), the Root Servers, the Internet Governance Forum and its regional counterparts … all of these were created at need and have adapted to changing technology and need.”

What do you wish you could go back and change?

“Sometimes I think it would have helped to have a larger IP address space at the beginning, but it would have been impossible to argue for it rationally. Now we do need IPv6 and its 128-bit address space. We are also in need of better security and resistance to various forms of cyber attack and malware. Whether installing public key crypto earlier would have helped is not clear given the academic nature of the network until 1989, but we can certainly use better security at all layers in the system.”

What do you think is one of the best moments in internet history?

“The first demonstration that the three original networks of the internet (ARPANET, PACKET RADIO NET and PACKET SATELLITE NET) all interworked with TCP/IP on Nov. 22, 1977, is a major milestone. So is the day we turned the internet on formally: Jan. 1, 1983. The appearance of commercial internet service in 1989 and the arrival of the World Wide Web also count as major milestones. The smartphone in 2007 heralded a new era for access to the internet.”

What do you think is one of the low points in internet history?

“The 15-year battle with the Open Systems Interconnection (OSI) effort from 1978 to 1993 for global standardization. The current-day battle with authoritarian governments that want to suppress freedom of speech and the constant battle with cyber-criminals who attack the users of the internet with harmful intent.”

Judy Estrin

Bloomberg | Getty Images

CEO of JLabs; co-founder of eight technology companies, including Bridge Communications, Network Computing Devices and Percept Software (acquired by Cisco Systems); former CTO of Cisco Systems.

What are you most proud of, with regards to your contributions to the internet?

“When I was at Stanford to do my MSEE I was fortunate to be part of the research group led by Vint Cerf that developed TCP -- the protocol of the internet -- and helped with the testing of the first implementations. The first company that I co-founded, Bridge Communications, helped bring networking and inter-networking to the commercial market.”

What do you wish you could go back and change?

“I am not sure if we really could have, but I wish that more focus on security had been built in from the beginning. On the other hand, if it had, there is a chance that it would have changed the architecture and limited its initial acceptance.”

What do you think is one of the best moments in internet history?

“There are so many great moments in the internet's journey from the research lab to the infrastructure that is so critical to all aspects of our lives. A few that I will highlight are: the integration of TCP into the Unix OS which led to its wide acceptance as the standard networking protocol; the introduction of the WWW and browser (and SSL which enabled ecommerce); the acceptance of the internet by the telephone companies including the integration of voice over IP.”

Related: 12 Pivotal Internet Moments That Forever Changed How We Live, Work and Play

What do you think is one of the low points in internet history?

“The incredible economic success of the internet has also led to some of its low points -- from security problems (hacks, identity theft and more) to a trend away from the more open democratic internet that amplified all voices to one that is moving back to ‘walled gardens' that amplify large brands and often makes it harder to be heard. I gave a TEDx talk a few years ago that goes into this point a bit more.”

Steve Case

The Case Foundation

Founder of America Online (AOL); chairman and CEO of Revolution LLC.

What are you most proud of, with regards to your contributions to the internet?

“Thirty years ago, I co-founded America Online. Back then, only 3 percent of U.S. households were online, and they were only online one hour a week. It took us nearly a decade to gain traction and get America online. I’m proud of being part of a team that made the internet part of everyday life.

“It wasn’t AOL alone. Cisco, Microsoft, AT&T and others built the infrastructure and educated people about what was then referred to as the information superhighway. At its core, what we built, and cultivated, was the first widespread online community.

“We were the first to allow millions of people to instant message with friends. We were the first to offer a complete online shopping experience. We were the first to partner with dozens of magazines and newspapers for instant access to news, and we helped give everybody a voice with message boards and blogs. For many Americans, AOL was, for its time, Google, Facebook, Twitter, Amazon, Spotify, YouTube and Instagram combined. At our peak, about half of U.S. internet traffic flowed through AOL.”

What do you wish you could go back and change?

“Needless to say, the fact that AOL led the way in the first wave, but to some extent lost its way in the second wave, is disappointing. Sometimes it has been hard to watch from the sidelines, but my efforts throughout the last 15 years have kept me busy. The work I’m doing at my investment firm Revolution, through the Case Foundation and my policy work are aimed at building on AOL’s efforts to democratize access to information by democratizing access to entrepreneurship -- and creating opportunity.”

What do you think is one of the best moments in internet history?

“It has been exciting to watch the evolution of the internet over the past three decades. It’s gone from something few knew or cared about to a capability we now can’t live without. But despite all that has happened, I think the best moments of the internet are still to come. I believe we’re on the cusp of a new era where the internet will be integrated into our lives in more seamless and pervasive ways. It’ll be more than the internet of things. It will be the internet of everything, transforming big industries like healthcare, transportation, education, energy, financial services and food, ultimately changing the way we live our lives in big ways. It’s what I call The Third Wave.

What do you think is one of the low points in internet history?

“While empowering in so many ways, the internet has also created risks. Terrorists use it to manage their attacks, and that has made us more vulnerable. As the internet becomes more central to our everyday lives, there are more risks to our privacy and security. It’s always a matter of balance. With new technologies there will always be a mix of benefits and risks. The challenge is to maximize the benefits and minimize the risks. This will become even more important in The Third Wave. We must get the policies right -- with entrepreneurs and policy makers working together.”

Naveen Jain

Mike Coppola | Getty Images

Currently, founder and executive chairman of Moon Express. Previously: founder and former CEO of Intelius; founder and former CEO of Infospace (now Blucora)

What are you most proud of, with regards to your contributions to the internet?

When InfoSpace was founded in 1996, there were no smartphones, but I realized that people wouldn’t want to carry PalmPilots, pagers, cell phones, etc. and would want all the content and services directly on their mobile device. We built the services for the mobile phone, including peer-to-peer payment and location-based services that we now take for granted but were revolutionary ideas 20 years ago.

“It was very clear from the early days of internet that new media brands would be created. Everyone was focused on building the brand, while InfoSpace became the first company to realize the value of being a brand behind the successful brands by syndicating the content to the new media sites.”

What do you wish you could go back and change?

“I won’t change a thing, because it was an amazing experience to be in the epicenter of the internet revolution and be part of making the history and not just watch the history being made. It was like surfing great waves where highs were higher than ever and lows were scary. No one knew what the business model was going to be, but we kept trying new ideas.”

What do you think is one of the best moments in internet history?

“I think the beginning of the internet in the late 1990s was a moment like no other. Creativity was at its highest and new business models were being created and destroyed at a faster rate than ever. I think Netscape changed the way we experienced the internet. AT&T CDPD phones (access to InfoSpace content was built right into these early phones) that were able to connect to internet like the dial-up modem was another historical moment in the history of the internet.”

What do you think is one of the low points in internet history?

“I think too much VC investment chasing bad ideas, causing valuation to be what was known as ‘Irrational Exuberance’ was the downfall of the first internet wave in the first half of 2000.”

David Bohnett

Michael Bulbenko

Founder of GeoCities (acquired by Yahoo)

What are you most proud of, with regards to your contributions to the internet?

“I'm most proud of creating GeoCities.com in 1994. GeoCities was significant in that we provided a thematic community-based structure for the creation of user-generated content and focused our whole effort on ensuring that our users felt their contribution and participation on GeoCities and within their online community was respected and appreciated. We developed tools and utilities that made it easy for our members to tell their friends about their site and that's how we tapped into the viral marketing potential of the web.

“In the early days of the commercialized internet it really was like the wild west; content models and economic models had yet to be developed and nobody had a sense of how the medium would evolve.

“It was extremely important to me to ensure that programming models be bottom up rather than top down. There were grand battles at the time between established media companies who were used to controlling what people watched and when they watched it and upstarts like GeoCities who saw the potential for new business models based on user-generated content and interactivity. GeoCities was a social media company before such a term existed. We were a forerunner. We attempted to create a company and business model that took advantage of the unique strengths of the medium. ‘People are sitting in front of a keyboard,’ I used to say, ‘let's give them a reason to use it.’”

What do you wish you could go back and change?

“Really, nothing. The organic growth of the internet and the development and evolution of high-speed connectivity and wireless technology were two key developments that brought us to today. If I could change anything it would be to accelerate the rate that these technologies were developed and deployed.”

Related: 15 Internet Relics We Miss (and Some We Don't)

What do you think is one of the best moments in internet history?

“The launch of Amazon.com.”

What do you think is one of the low points in internet history?

“The rise of Facebook and its facilitation of the celebration of self.”

Steven Lerner

Steven Lerner

Founder and CEO of AlbinoBlackSheep.com

What are you most proud of, with regards to your contributions to the internet?

“I worked very hard on the internet, but I'll never be certain if I contributed to what the internet has become or if it was going in that direction anyways. I'm still happy when I am credited for making memes possible and when people tell me my site helped them through hard times.

“I made sure to credit the authors from the beginning, even when they failed to include credits in their own videos. Then I got really into authors protecting their rights, and I got really into intellectual property law for the average internet contributor.”

What do you wish you could go back and change?

“Everyone wants to change something for their own personal gain rather than the greater good, and I am no exception. When Janet Jackson's Super Bowl nipple slip happened, I was given high-resolution footage of it. Even though millions of people were searching for it, I chose not to post it. It didn't fit in with the style of my content. I later talked with a guy who did post it on his site, and he said it was a million-dollar decision that changed his life forever. Whoops!

“At the height of its popularity, in 2005 or 2006, I was wanting to take Albino Blacksheep to the next level, which I thought was television and traditional media. ... So I just assumed if I spent energy putting these animations on television and putting together a television pilot, that would actually grow Albino Blacksheep. But it took away time and resources from the internet version of Albino Blacksheep, which was much more important.”

What do you think is one of the best moments in internet history?

“I live in a viral world of collective consciousness. So the best moments are watching things crash and burn almost instantly. Take the Kony 2012 phenomenon, for example. Everyone seemed obsessed with this African political issue. Dozens of celebrities all lined up, talking about the dangers of Kony. It seemed very manufactured. Smart people began questioning the charity behind it, Invisible Children. ... Then, just a couple weeks later, the internet together as a whole watches video footage of the founder of its charity high on drugs nude in the streets vandalizing cars and acting crazy. It seems like a low point, but it’s actually a high point that everyone gets together and realizes the reality of the situation.

“The Anonymous movement's success against the Church of Scientology allowed people to believe the internet can make a real-world difference against even the largest institutions. More and more internet-led political movements occurred afterwards, for good or for bad (ISIS uses the internet to find recruits), but it was now possible for individuals to make a difference in the world from behind their desk and phones.”

What do you think is one of the low points in internet history?

“One of the low points I remember is Reddit users falsely accusing someone of being the Boston Marathon bomber while the police investigation was occurring. This person killed themselves over the hatred they got from the internet users. A lot of people have killed themselves due to all sorts of finger-pointing and bullying from internet users. People don't realize that being significant on the internet feels like having the attention of the whole world all at once, continuously and forever. If the internet hates you, it's too much shame and attention for most people to handle. I think Albino Blacksheep users have bullied some people to their suicide, but it's hard to confirm, but they definitely have bullied many people into disconnecting.”

Brian Shuster

Utherverse Digital, Inc.

Internet advertising pioneer and patent holder of several internet technologies, including the pop-under ad; CEO of Ideaflood, Inc.; CEO of Utherverse Digital, Inc.

What are you most proud of, with regards to your contributions to the internet?

“Back in 1995, I put up the first banner ads. I actually developed, with a NASA/JPL engineer who was working with me at the time, the very first script to be able to track advertisements placed on websites and to count clicks on those ads and take people to the correct website.

"In the course of my doing this, I got a huge amount, an unbelievable amount of hate mail and death threats, and all kinds of negative response from the educational community who felt that the internet and the web should be noncommercial, and that it was not for the general public, it was for professionals in the education field …

"Suddenly, websites had a mechanic by which they could generate revenue … immediately, once banners had a foothold, the web exploded. I go to bed at night often thinking about how that one innovation to the web has radically changed the world we live in.”

What do you wish you could go back and change?

"It’s not so much as a regret as a sadness I have. When pop-unders became rampant, you would go to a website, and it would oftentimes crash your browser, because 50 pop-ups and pop-unders would launch when you tried to leave the website. And the advertiser was getting paid maybe half a penny for every pop-up they launched, so they would launch as many as they could launch until your browser crashed.

“It’s hard to overstate just how obnoxious and, I mean, there was a period where using the internet was like, oh, God, I’ve got to sit down, and I’m going to go to this one website that I trust that isn’t going to crash my machine, and if there’s a hyperlink I’m going to throw the dice.

“If I had received the patent in a timely fashion, I would have been able to prevent the abuse of pop-unders. I had no teeth, I couldn’t enforce it, because the patent hadn’t been issued. It was pending for 14 years! So by the time they issued it, pop-unders were no longer a problem. But the damage had already been done. And that was substantial damage that really crippled the web for a long time, and the impact is still with us today.”

What do you think is one of the best moments in internet history?

“I remember the shock that I felt when I was first using a search engine, and that search engine being AltaVista, where I could type in a search term and within just a fraction of a second have results that were actually good results and relevant to my question.

“It was something I didn’t actually believe could happen. I think that was probably the moment when I realized everything was different. I no longer needed to have an encyclopedia to look things up. You could just have a database online of all the world’s knowledge at your fingertips.”

What do you think is one of the low points in internet history?

“I don’t think you’re going to hear this from anyone but me, but the low point of the internet, and it is my firm belief that the stock crash that occurred in 2000 for the internet, and all of the problems and the setbacks that the web suffered, I lay the blame for all of that squarely on Visa.

“What we see now is that the business models and plans that were built and oftentimes underway in the late '90s were in fact valid business models and were in fact valued correctly. It should not have been considered a bubble.

“There was a very limited way to accept payments online in the '90s. Those payments were mostly from Visa and MasterCard. You didn’t have alternative methods for a person to pay for something. But Visa had no real ability to validate that the person using a credit card to buy something was in fact the owner of the card. This is before PINs, this is before the CV2s, this is before any real address verification.

“The dark side of this was, anybody, for any reason, could call up their bank and say, ‘I want my money back on that charge.’ And Visa would give them their money back. Now, the goods and services had already been delivered, at that point. But it became much more sinister. Visa would also fine the merchants.

“Companies were fined out of business. The entire economy crashed as a consequence of this.”

Max Levchin

Bloomberg | Getty Images

Co-founder and CEO of Affirm; co-founder and chairman of Glow; co-founder and CEO of Slide (acquired by Google); co-founder and former CTO of PayPal

What are you most proud of, with regards to your contributions to the internet?

“There were a few companies that fundamentally shifted things from being an information exchange to a value exchange, and PayPal was one of them.”

What do you wish you could go back and change?

“There isn't anything I would really change. I don't give in to regret. I do make plenty of mistakes, but I don't regret them.”

What do you think is one of the best moments in internet history?

“For the World Wide Web, the introduction of Mosaic (which became Netscape), which was the first graphical browser, fundamentally changing how people saw what the web was. Mosaic introduced the embedded image, and it became clear that this would change everything.”

Related: 15 Throwback Web Pages That Show Us How the Internet Has Changed

What do you think is one of the low points in internet history?

“I don't see any low points. I think people's perspectives on this can be limiting. For example, every decade, there is always the demise of some startup that everyone promptly deems the collective delusion. Yet, it often emerges again as a great and successful idea five or 10 years later.”

Langley Steinert

CarGurus

Founder and CEO of CarGurus; co-founder and former chairman of TripAdvisor

What are you most proud of, with regards to your contributions to the internet?

"I’ve taken many entrepreneurial steps over the years, and I am quite proud of the path that has taken me to this place in my career. Looking back, I would say that I am most proud of helping to bring transparent experiences to two otherwise opaque and disguised industries -- first with hotel reviews at TripAdvisor and now with car prices and dealer reputation at CarGurus."

What do you wish you could go back and change?

"Building scalable businesses is extremely hard, yet rewarding work, and I thoroughly enjoy it. However, I wish that I took a year off after leaving TripAdvisor and spent some time decompressing before starting to delve into the online car shopping experience. Perhaps a year of windsurfing might have been nice."

What do you think is one of the best moments in internet history?

"The internet’s history is rich with fantastic moments, but Facebook’s launch is the one that sticks out the most to me. Facebook made the internet less of a one-to-one experience and more of a group connection. It has really has transformed the internet into the social experience it is today."

What do you think is one of the low points in internet history?