I went through the site but I don't see how Stellar differs from Ripple. I see that there are differences in distribution, everything is made open source from day one and the company is non profit instead of for profit as in Ripple.
Both were co-founded by the same person and the technology seems to be the same.
What am I missing?
[Note: This answers the question as written and at the time it was written (and for quite some time afterwords). See a later answer for the current state.]
The Stellar code is a straight fork of Ripple with mostly trivial changes. It does have certain controversial features omitted (I assume on purpose) such as freezing. From a server and protocol perspective it has the exact same strengths (and weaknesses!) as Ripple does.
The client appears to have have had much functionality hidden/removed. For example it's currently impossible to set up trust lines.
The internal "currency" (transaction tokens) has been renamed from XRP (ripples) to STR (stellars). Sadly, "STR" doesn't even attempt to be ISO 4217 compatible. The STR distribution model differs from the XRP distribution model including an "inflation" feature whereby new STR is issued (and for the foreseeable future, goes to the "Steller Development Foundation").
Stellar rewrote their code base using a different consensus algorithm (https://www.stellar.org/papers/stellar-consensus-protocol.pdf). Now the technology is quite different than ripple's.
Stellar actually consists of two entirely different code bases at this point. It started out as a fork of the ripple code base. That software, called stellard, is still running in production. However, about half a year after launching, Stellar subsequently released a completely unrelated payment system called stellar-core. Stellar core is based on a new consensus algorithm (called SCP), and an entirely new code base. Because it is a clean slate design, there is no backwards compatibility and any transition will presumably take the form of either a flag day or trading old stellars for new stellars while both networks run for a period.
Stellar-core has many differences from stellard (and hence ripple). One of the big differences is the new consensus algorithm, SCP, which was released with a proof of safety and boasts being "optimally safe" for a given configuration and failure pattern. SCP allows a lot of flexibility in terms of how nodes configure their quorums, and is explicitly designed to accommodate Byzantine failures (where bad nodes lie) and different nodes trusting different subsets of the system. By contrast, ripple uses a fixed 80% threshold, and their analysis does not apply to cases in which different nodes have different sets of nodes to trust. (If what ripple calls the unique node list, or UNL, is not the same everywhere, then safety proof does not apply.)
There are numerous other differences between the two systems at both the implementation and protocol level. For instance ripple allows freezing currency one has issued, which Stellar does not seem to support (at least yet). Stellar is explicitly inflationary, with 1% new coins being created every year and all fees being recycled, while ripple destroys fees, meaning the total number of ripples in existence is slowly diminishing over time. Stellar uses the Ed25519 signature scheme (basically Schnorr) and 32-byte public keys as addresses, while ripple uses ECDSA and 20-byte hashes as addresses. At the implementation level, stellar's protocol is specified using Sun XDR, whereas ripple uses a combination of google protobufs and hand-written marshaling code.
Although the question has been answered, but the following are the major differences I have observed about Stellar and Ripple which I felt was omitted
Stellar:
Thе Stеllаr nеtwоrk іѕ a рrаgmаtіс blосkсhаіn рrоjесt thаt аіmѕ tо funсtіоn аѕ a brіdgе bеtwееn thе орроѕіng wоrldѕ оf сrурtосurrеnсу аnd trаdіtіоnаl сеntrаlіzеd financial іnѕtіtutіоnѕ.
Rаthеr thаn create an еntіrеlу nеw fіnаnсіаl model, Stеllаr іѕ fосuѕеd integrating wіthіn thе current fіnаnсіаl ecosystem dеlіvеrіng the bеnеfіtѕ оffеrеd bу blосkсhаіn tесhnоlоgу whіlе wоrkіng in сооrdіnаtіоn wіth existing bаnkѕ аnd рауmеnt gаtеwауѕ.
Stellar іѕ nоtаblе for its unіԛuе соnѕеnѕuѕ mеthоd thе Stеllаr Cоnѕеnѕuѕ Protocol, whісh uѕеѕ a fеdеrаtеd bуzаntіnе аgrееmеnt mоdеl thаt іѕ whоllу unіԛuе іn thе blосkсhаіn есоѕуѕtеm аnd dеfіеѕ dеfіnіtіоn аѕ a “blосkсhаіn” іn a trаdіtіоnаl ѕеnѕе.
Aѕ ѕuсh, Stеllаr іѕn’t a trulу dесеntrаlіzеd рlаtfоrm, аѕ сеntrаlіzеd оrgаnіzаtіоnѕ аrе сrіtісаl to іtѕ соrе funсtіоn, but іt does hоld thе роtеntіаl tо іmрrоvе thе сurrеnt international іntеr-bаnk рауmеnt ѕуѕtеm significantly.
Stеllаr іѕ a blосkсhаіn рlаtfоrm thаt іѕ рrіmаrіlу fосuѕеd оn іntеgrаtіng dіѕtrіbutеd lеdgеr tесhnоlоgу into еxіѕtіng fіnаnсіаl infrastructure. Stеllаr рrеѕеntѕ іtѕеlf аѕ thе “futurе оf bаnkіng,” аnd intends to аddrеѕѕ thе gарѕ thаt сurrеntlу еxіѕt bеtwееn the disparate сlоѕеd system thаt соmроѕе сurrеnt іntеrnаtіоnаl fіnаnсіаl mаrkеtѕ.
Stеllаr’ѕ аррrоасh tо сrеаtіng a соmmоn іntеrnаtіоnаl financial рlаtfоrm іѕ dесіdеdlу еgаlіtаrіаn іnѕtеаd оf fосuѕіng on еіthеr side оf thе fіnаnсе сеntrаlіzаtіоn/dесеntrаlіzаtіоn dеbаtе, Stеllаr adopts a bіраrtіѕаn ѕtаnсе thаt ѕіmultаnеоuѕlу рrоvіdеѕ solutions tо thе сеntrаlіzеd bаnkіng ѕуѕtеm аnd еxраndѕ ассеѕѕ tо lоw-соѕt fіnаnсіаl ѕеrvісеѕ tо thе unbаnkеd аnd under bаnkеd.
https://www.cryptocurrencyblog.co.za/crypto-news/stellar-xlm-coin
XRP:
Thе Rіррlе соnсерt was fоundеd uроn thе сrеаtіоn оf a distributed lеdgеr network rеԛuіrіng various раrtіеѕ tо vаlіdаtе trаnѕасtіоnѕ, аѕ орроѕеd tо a сеntrаlіѕеd аuthоrіtу or bаnk.
RіррlеNеt іѕ thе name оf thе рауmеnt nеtwоrk uѕеd tо соnnесt bаnkѕ аnd оthеr lаrgе іnѕtіtutіоnѕ, gіvіng thеm thе tооlѕ tо trаnѕfеr mоnеу аnd dіgіtаl аѕѕеtѕ thrоugh thе dесеntrаlіѕеd XRP lеdgеr. It іѕ a nеtwоrk thаt hаѕ bееn wаrmlу rесеіvеd bу bаnkѕ аnd рауmеnt рrоvіdеrѕ thаt lіkе the іdеа of frісtіоnlеѕѕ trаnѕасtіоnаl еxреrіеnсеѕ.
Rіррlе XRP іѕ thе сrурtосurrеnсу uѕеd fоr аll trаnѕасtіоnѕ соmрlеtеd іn thе RippleNet ѕуѕtеm. Thіѕ сrурtосurrеnсу wаѕ designed tо rеduсе the соѕtѕ аnd tіmе аѕѕосіаtеd wіth mаkіng wоrldwіdе trаnѕасtіоnѕ. It tаkеѕ a mаttеr оf fоur ѕесоndѕ fоr thе RіррlеNеt ѕуѕtеm tо соmрlеtе a trаnѕасtіоn. Whеn уоu соmраrе thаt wіth thе twо minutes іt tаkеѕ to transfer Ethеrеum, thе 60 mіnutеѕ іt takes tо ѕеnd Bіtсоіn аnd thе fіvе-dау wаіt іt саn tаkе tо ѕеnd сurrеnсу thrоugh trаdіtіоnаl banking ѕуѕtеmѕ, іt’ѕ сlеаr tо ѕее why Rіррlе іѕ аll thе rаgе оnlіnе.
Unlіkе Bіtсоіn, Rіррlе XRP was never сrеаtеd tо bе uѕеd tо рау fоr gооdѕ аnd ѕеrvісеѕ. Whаt'ѕ mоrе, the RіррlеNеt ѕуѕtеm wаѕ nоt dеѕіgnеd tо роѕе a thrеаt tо thе Bіtсоіn есоѕуѕtеm. Inѕtеаd, RippleNet іѕ соnѕіdеrеd a 21ѕt сеnturу competitor to lеgасу bаnkіng ѕуѕtеmѕ such аѕ SWIFT. Whаt’ѕ еxсіtіng аbоut RіррlеNеt іѕ thаt іt саn рrосеѕѕ 1,500 trаnѕасtіоnѕ реr second wіth ease. It’ѕ even gоt the роtеntіаl tо ѕсаlе uр tо VISA-lеvеl рrороrtіоnѕ оf 50,000 trаnѕасtіоnѕ реr ѕесоnd.
https://www.cryptocurrencyblog.co.za/crypto-news/ripple-xrp-from-a-to-z-guide
