CONTACTS:

Gary Baker, Juno Public Relations
(212) 597-9005 or pr@support.juno.com

Becky Yeamans, Juno Investor Relations
(212) 597-9274 or ir@support.juno.com

JUNO ANNOUNCES VIRTUAL SUPERCOMPUTER PROJECT

DISTRIBUTED COMPUTING FACILITY TO HARNESS UNUSED RESOURCES OF JUNO SUBSCRIBER
BASE, WITH THEORETICAL COMPUTING POWER OF WORLD'S FASTEST SUPERCOMPUTER

NEW YORK, NY (February 1, 2001) -- Juno Online Services, Inc. (Nasdaq: JWEB)
today announced the establishment of the Juno Virtual Supercomputer Project, a
distributed computing effort of unprecedented scope that aims to harness unused
processing power associated with the free portion of its subscriber base in
order to execute computationally intensive biomedical and other applications on
behalf of commercial clients and research institutions.

Juno is one of the nation's largest Internet access providers, with 14.2 million
total registered subscribers and 4.0 million active subscribers in December
2000. While the personal computers owned by different Juno subscribers have
different performance characteristics, preliminary studies recently completed by
the company suggest that if the computers of all of Juno's active free
subscriber base were simultaneously working on a single computational problem,
they would together represent the world's fastest supercomputer (measured in
terms of aggregate instructions per second), and might approach or break the
"petahertz barrier" (with a hypothetical effective processor speed on the order
of a billion megahertz). Although the achievable effective computing power (and
the level of any associated revenues) are likely to be significantly lower in
practice for a variety of reasons, Juno's management believes that the unused
computing power of its free subscriber base represents a potentially valuable
asset from the viewpoint of both potential revenue generation and potential
contribution to society.

The company expects to focus particular attention on prospective clients
involved in bioinformatics research who are beginning to confront such
computationally demanding applications as the determination of the structure of
proteins encoded by gene sequences discovered through recently completed efforts
to sequence the human genome, and searching through millions of "virtual
molecules" to find promising candidates for new pharmaceutical products. Juno's
management believes that many such problems can be effectively divided into a
large number of smaller computational tasks in such a way as to capture
substantial potential gains in both speed and cost-effectiveness by comparison
with traditional supercomputing approaches. Additionally, Juno's service is
designed to make it possible for customers to access very large amounts of
processing power over relatively short periods of time without




having to bear the high overhead costs associated with the in-house acquisition
or rental of conventional supercomputers or "computer farms."

The Juno Virtual Supercomputer Project will make use of patented technology Juno
currently employs in connection with its display of advertising to download
computational tasks to subscribers' computers for processing offline during time
when such subscribers are not using their computers. The results of such offline
computations will then be uploaded to Juno's central computers during a
subsequent connection, in much the same way that Juno currently collects
responses to the advertisements it shows offline. Applications will run as
"screen savers" on the computers of participating subscribers when their
machines would otherwise be idle, performing calculations when the computer is
on but not in use. Neither the download nor the operation of these applications
are expected to have any significant impact on the user experience or on the
connection speeds subscribers experience while using Juno.

Initially, Juno expects to recruit volunteers from among its millions of
subscribers to provide the computing power required for its early virtual
supercomputing activities. Subscribers to Juno's free basic service may
ultimately be required to make their unused computing power available to the
project as a condition for using that service. While the company's billable
subscribers may be offered the opportunity to participate on a strictly optional
basis in order to advance biomedical research and/or other forms of scientific
and technical progress, the company does not currently expect to require the
participation of such subscribers.

Juno also announced today that it has hired Yury Rozenman, formerly of Applied
Biosystems, to spearhead the Juno Virtual Supercomputer Project. Mr. Rozenman,
who joined Juno earlier this month as a vice president, comes to the company
with more than 13 years of scientific and bioinformatics experience,
predominantly in protein and DNA analysis and its application to understanding
biological processes.

"Pharmaceutical firms spend many years, and an estimated $400 million dollars,
for every drug that is eventually brought to market," commented Rozenman. "To
the extent that groundbreaking new applications software running on Juno's
Virtual Supercomputer is able to bring lifesaving new drugs to market in a
fraction of the time and at a fraction of the cost, this could be enormously
valuable from both an economic and a human perspective."

"We are excited about the prospect of teaming up with our subscribers to offer
researchers a supercomputing tool of extraordinary power," said Charles Ardai,
Juno's president and chief executive officer. "We believe this project has the
potential to further diversify our revenue streams, and in particular, to enable
us to derive additional revenue from our free subscribers. If we can do so while
making a significant contribution to biomedical research, this would be even
more gratifying."

ABOUT JUNO
Juno Online Services, Inc. is one of the nation's leading Internet access
providers, with 14.2 million total registered subscribers as of December 31,
2000, and 4.0 million active subscribers during that month.



Founded in 1995, Juno provides multiple levels of service, including free basic
Internet access, billable premium dial-up service, and (in certain markets)
high-speed broadband access. The company's revenues are derived primarily from
the subscription fees charged for its billable premium services, from the sale
of advertising, and from various forms of electronic commerce.

For more information about Juno, visit www.juno.com/corp. To get a copy of the
Juno software, go to www.juno.com or call 1-800-TRY-JUNO.

                                       ###

STATEMENTS IN THIS PRESS RELEASE REGARDING JUNO ONLINE SERVICES, INC. THAT ARE
NOT HISTORICAL FACTS ARE FORWARD-LOOKING STATEMENTS AND ARE SUBJECT TO RISKS AND
UNCERTAINTIES THAT COULD CAUSE SUCH STATEMENTS TO DIFFER MATERIALLY FROM ACTUAL
FUTURE EVENTS OR RESULTS. ANY SUCH FORWARD-LOOKING STATEMENTS ARE MADE PURSUANT
TO THE SAFE HARBOR PROVISIONS OF THE PRIVATE SECURITIES LITIGATION REFORM ACT OF
1995. THE FOLLOWING FACTORS, AMONG OTHERS, COULD CAUSE JUNO'S ACTUAL RESULTS TO
DIFFER MATERIALLY FROM THOSE DESCRIBED IN A FORWARD-LOOKING STATEMENT: LIMITED
HISTORY OF OFFERING JUNO'S BILLABLE PREMIUM SERVICES AND FREE BASIC SERVICE IN
ITS CURRENT FORM; HISTORY OF LOSSES; FAILURE TO RETAIN OR GROW JUNO'S SUBSCRIBER
BASE; INCREASING COMPETITION FROM EXISTING OR NEW COMPETITORS; INABILITY TO
SUSTAIN CURRENT LEVELS OF SUBSCRIBER ACQUISITION OR RETENTION; INABILITY TO
SUCCESSFULLY MIGRATE FREE SUBSCRIBERS TO, OR TO RETAIN SUBSCRIBERS IN, JUNO'S
BILLABLE PREMIUM SERVICES; RAPID TECHNOLOGICAL CHANGE; POSSIBLE UNAVAILABILITY
OF FINANCING AS AND IF NEEDED; DECREASES IN THE POPULARITY OF THE INTERNET AMONG
CONSUMERS OR AS AN ADVERTISING MEDIUM; SPECIFIC RISKS ASSOCIATED WITH THE
DEVELOPMENT AND IMPLEMENTATION OF THE JUNO VIRTUAL SUPERCOMPUTER PROJECT
DESCRIBED ABOVE, INCLUDING RISKS THAT JUNO WILL BE UNABLE TO DERIVE REVENUE FROM
THE PROGRAM AND RISKS RELATING TO SUBSCRIBER ACCEPTANCE OF THE PROGRAM, AMONG
OTHERS; POSSIBLE INDUSTRY CONSOLIDATION; AND POTENTIAL FLUCTUATIONS IN QUARTERLY
AND ANNUAL RESULTS. THIS LIST IS INTENDED TO IDENTIFY ONLY CERTAIN OF THE
PRINCIPAL FACTORS THAT COULD CAUSE ACTUAL RESULTS TO DIFFER. READERS ARE
REFERRED TO THE REPORTS AND DOCUMENTS FILED BY JUNO WITH THE SECURITIES AND
EXCHANGE COMMISSION, INCLUDING THE QUARTERLY REPORT ON FORM 10-Q FILED NOVEMBER
14, 2000 AND THE REGISTRATION STATEMENTS ON FORM S-3 FILED ON NOVEMBER 28, 2000,
AS SUBSEQUENTLY AMENDED, FOR A DISCUSSION OF THESE AND OTHER IMPORTANT RISK
FACTORS.